Yan et al. BMC Pediatrics(2024) 24:532
https://doi.org/10.1186/s12887-024-04973-y

BMC Pediatrics

RESEARCH

Open Access

Clinical, pathological and genetic
characteristics of 17 unrelated children
with Alagille Syndrome
Jianguo Yan2†, Yuanzhi Huang1,2†, Lili Cao2, Yi Dong2, Zhiqiang Xu2, Fuchuan Wang2, Yinjie Gao2, Danni Feng2 and
Min Zhang1,2*
Abstract
Background Alagille syndrome (ALGS) is a multisystem genetic disorder frequently characterized by hepatic
manifestations. This study analyzed the clinical, pathological, and molecular genetic features of ALGS to improve theefficiency of clinical diagnosis.
Methods We retrospectively analyzed the clinical manifestations, pathological examination findings, and genetic
testing results of 17 children diagnosed with ALGS based on the revised criteria and hospitalized at our center fromJanuary 2012 to January 2022.
Results The clinical manifestations are as follows: Cholestasis (16/17, 94%), characteristic facies (15/17, 88%), heartdisease (12/16, 75%), butterfly vertebrae (12/17, 71%) and posterior embryotoxon (7/12, 58%). Among the 15 patients
who underwent liver pathology examination, 13 (87%) were found to have varying degrees of bile duct paucity.
Genetic testing was performed on 15 children, and pathogenic variants of the jagged canonical Notch ligand 1 (JAG1)
gene were identified in 13 individuals, including 4 novel variants. No pathogenic variant in the notch homolog 2(NOTCH2) gene were identified, and 2 children exhibited none of the aforementioned gene pathogenic variants. The
median follow-up duration was 7 years. Of the remaining 15 patients (excluding 2 lost to follow-up), 11 remained
stable, 4 deteriorated, and no patient died during the follow-up period.
Conclusions Among children diagnosed with ALGS, cholestasis stands as the most common feature. To minimize
the risk of misdiagnosis, genetic testing should be performed on children exhibiting cholestasis, followed by theapplication of the revised diagnostic criteria for ALGS. While pharmacological therapy has shown effectiveness for
ALGS patients, liver transplantation may be considered in instances of severe pruritus.
Keywords Alagille syndrome, Clinical manifestation, Cholestasis, Genetic analysis†

Jianguo Yan and Yuanzhi Huang contributed equally to this work.

*Correspondence:
Min Zhang
gcmw2001@163.com
1
Peking University 302 Clinical Medical School, 38 Xueyuan Road,
100191 Beijing, China
2
Senior Department of Liver Diseases, The Fifth Medical Center of Chinese
PLA General Hospital, Beijing, China© The Author(s) 2024. Open Access This article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0
International License, which permits any non-commercial use, sharing, distribution and reproduction in any medium or format, as long as you
give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if you modified thelicensed material. You do not have permission under this licence to share adapted material derived from this article or parts of it. The images orother third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to thematerial. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation
or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://
creativecommons.org/licenses/by-nc-nd/4.0/.

Yan et al. BMC Pediatrics(2024) 24:532

Introduction
Alagille Syndrome (ALGS) is a rare multisystem disorder with an estimated incidence rate ranging from 1 in
30,000 to 1 in 100,000 individuals [1]. It is inherited in
an autosomal dominant manner in approximately 40% of
patients [2]. ALGS is primarily attributed to pathogenic
variants in the jagged canonical Notch ligand 1 (JAG1)
and Notch Homolog 2 (NOTCH2) genes, which encode
molecules involved in the NOTCH signaling pathway [3–5]. The severity of ALGS can range from asymptomaticpresentations to fatal complications, with a mortality rate
reaching up to 10% [4, 6, 7]. The clinical manifestationsof ALGS are diverse, including cholestasis, characteristic
facies, posterior embryotoxon, abnormal developmentof the heart and bones, kidney and vascular abnormalities in some patients, and liver histopathology may reveal
the absence of intrahepatic bile ducts [2]. However, due
to the variable expressivity of clinical manifestations
among ALGS patients, some exhibit only a single typicalsymptom, and some are even in a subclinical state whenseeking medical attention [8–12]. Consequently, relying
on classical diagnostic criteria may lead to overlooking
the diagnosis of ALGS [13, 14]. The current diagnosis
primarily relies on the revised diagnostic criteria introduced in 2007 [15, 16], which incorporate genetic testing to improve diagnosis accuracy. We retrospectively
analyzed the clinical data of 17 children diagnosed with
ALGS at our hospital over the past 10 years, aiming toprovide compelling evidence supporting the early detection of ALGS.
Materials and methods
Patients

The study enrolled 17 children diagnosed with ALGS who
were admitted to the Fifth Medical Center of the PLA
General Hospital from January 2012 to January 2022.
ALGS diagnosis was established based on the revised
criteria [15, 16], excluding children with comorbidities.
Cholestasis was defined by elevated serum direct/conjugated bilirubin levels (> 1.0 mg/dL or > 17µmol/L), or by
gamma-glutamyl transpeptidase (GGT) levels surpassing
3 times the upper limit of normal [17, 18]. Characteristic
facies is described as an inverted triangular face, definedby a prominent forehead, deep-set eyes with hypertelorism, a straight nose with a bulbous tip, and a pointed
chin [2].
Clinical data were gathered from medical records andfollow-up visits. At diagnosis, demographic characteristics and clinical data were recorded, including clinicalsymptoms, laboratory data (liver function and lipid tests),
physical examination results (growth and development
condition, facial features, and indications associated withchronic hepatitis, such as jaundice, spider nevi, or palmar
erythema), routine examinations (cardiac and abdominal

Page 2 of 12

ultrasound, chest and abdominal Computed Tomography, abdominal Magnetic Resonance Imaging, and spinal
X-ray), and specialist examinations (ophthalmic slit-lamp
examination). Additionally, results from liver biopsy andgenetic testing were obtained. The study was ethicallyapproved by the Ethics Committee at the Fifth Medical
Center of the PLA General Hospital. All clinical information and images presented in this report were acquiredwith prior written consent from the patients’ parents.
Percutaneous liver pathology

Percutaneous liver biopsies were performed on 15 cases.
The paraffin-embedded tissue was sectioned and stainedwith hematoxylin, eosin, Masson’s trichrome, cytokeratin-7 and cytokeratin-19. The histological examination
was reviewed by experienced pathologists. Bile duct paucity was defined as the absence of interlobular bile ducts
in at least 50% of the portal tracts within liver samples
containing 10 or more portal areas [19].
Genetic variation analysis

DNA was extracted from peripheral blood, with detailed
methodology outlined in the previous publications [20,21]. Briefly, the sequenced data were then aligned withthe human reference genome version 19 (hg19) using
the Burrows-Wheeler Alignment (BWA) Tool (http://
bio-bwa.sourceforge.net/). The Genome Analysis Toolkit (GATK) software (www.broadinstitute.org/gatk) wasused to analyze single-nucleotide polymorphisms (SNPs).
ANNOtation VARiants (ANNOVAR) was utilized forannotating candidate variants(annovar.openbioinformatics.org/en/latest/). MutationTaster [22], Sorting Intolerant From Tolerant (SIFT) [23, 24] and Polyphen-2 [25]programs were used to predict the potential impacts ofsingle-nucleotide variants (SNVs). Following the American College of Medical Genetics and Genomics (ACMG)
guideline [26], pathogenic variants were classified as
benign, likely benign, variants of unknown clinical significance (VUS), likely pathogenic and pathogenic. The
candidate causal variants identified via whole-exome
sequencing (WES) were subsequently confirmed using
Sanger sequencing. Co-segregation analyses were also
performed within the patient’s family. Fragments covering mutated sites were amplified, purified with the Zymoclean Polymerase Chain Reaction (PCR) Purification Kit(Zymo Research, USA), and sequenced using an ABI3730 DNA Sequencer (SeqGen, CA). Sanger sequencing
data were analyzed by Chromas Lite v2.01 (Technelysium
Pty Ltd., Tewantin, QLD, Australia).
Treatment and follow-up

Except for 2 patients who opted out of medication
owing to their mild symptoms, the other 15 patients
underwent prolonged oral therapy, which comprised

Yan et al. BMC Pediatrics(2024) 24:532

of ursodeoxycholic acid, cholestyramine, bicyclic alcohol, and compound glycyrrhizin tablets, as well as various vitamin supplements. Children exhibiting severecholestasis or pruritus underwent liver transplantation.
Every three months, the children’s liver function, biochemistry, blood routine, and abdominal ultrasound werereviewed, along with regular assessments of their growthand development. Treatment adjustments were made inaccordance with changes in the patients’ conditions. All
patients were followed up until August 2023.
Statistical analysis

Continuous variables were shown as medians and interquartile ranges. Categorical variables were presented
as counts and percentages. Statistical analysis was performed with R Foundation for Statistical Computing
software (v. 4.1.3; Vienna, Austria; http://www.r-project.
org/).

Results
Clinical characteristics

This study included a total of 17 participants, with 10
males and 7 females. The median age of onset among the
17 children was 2 months (range: 1-168 months), withmost developing the disease within 3 months of birth.
The median age at diagnosis was 5 years (range: 1–15
years).
All patients in the study exhibited liver involvement.
Cholestasis was the most prevalent characteristic, affecting 94% of the patients (16/17). Characteristic facies wasPage 3 of 12

the second most prevalent, presenting in 88% of patients(15/17) (Fig. 1). Heart disease was identified in 75% of
patients (12/16), and butterfly vertebrae were detected
in 71% (12/17) (Fig. 2). The posterior embryotoxon
was detected in approximately 58% of patients (7/12)
assessed. Growth retardation was observed in 53% of thechildren (9/17), and pruritus was reported by 42% (7/17).
Only Patient 8 had a relevant family history, specificallya history of ALGS in an elder brother. Abdominal MRI
scans revealed cirrhosis with ascites in patients 5 and11, which was histologically confirmed. Both patients,
aged over 10 years, exhibited significant cholestasis uponadmission. Detailed clinical information for each patientis provided in Table 1 and Supplementary Table 1.
Biochemical results

Laboratory examination indicators for all patients arepresented in Table 2. AST, GGT, and LAP levels were
elevated in all patients. Total biliary acid (TBA) was
increased in 16 patients (94%), LAP in fifteen patients(88%), alanine aminotransferase (ALT) in thirteen
patients (76%), total cholesterol (TC) in thirteen patients(76%), triglycerides (TG) in twelve patients (71%), DBil inseven patients (42%), and alkaline phosphatase (ALP) levels in five patients (29%).
Histological results

15 children underwent liver biopsy for pathology examination, revealing intrahepatic bile duct paucity in 12
cases (Fig. 3). Mild liver inflammation and fibrosis were

Fig. 1 Characteristic facies of Alagille syndrome in case 2: a child aged 1 year and 7 months with a prominent forehead, deep-set eyes with hypertelorism,a straight nose with a bulbous tip, and a pointed chinYan et al. BMC Pediatrics(2024) 24:532

Page 4 of 12

Fig. 2 Butterfly vertebrae in case 11 (The lesions occurred in the thoracic vertebra region, as indicated by an arrow)both present in 14 patients. The liver biopsy of one
patient indicated cirrhosis (Table 3 and supplementary
Table 2).
Genetic test results

Among the 15 individuals subjected to genetic testing,
13 carried pathogenic variants in the JAG1 gene, while
none exhibited pathogenic variants in the NOTCH2 gene.
No JAG1 gene pathogenic variants were detected in twopatients. Thirteen distinct pathogenic variants in the
JAG1 gene were identified in the 13 children harboringsuch variants, comprising six frameshift, three nonsense,
two missense, one splice-site mutation, and one large
fragment heterozygosity loss. Four novel pathogenic variants in the JAG1 gene were identified in our study. All
pathogenic variants identified in our study were either
previously reported or predicted to be pathogenic. The
amino acid changes induced by these pathogenic variants are located at diverse positions on the JAG1 protein.
Bioinformatics software was used to assess the pathogenicity of an unreported missense mutation, c.548T > A(p.I183N), which was deemed harmful by MutationTaster, SIFT, and Polyphen-2 (Table 4, Fig. 4 and Fig. S1).
Management and follow-up

After a period of treatment, most children demonstrated
improved liver function test results, yet their pruritus
did not experience significant relief. Liver transplantation was performed for case 8 (presenting with severe
pruritus and stunted growth) and case 11 (suffering fromsevere cholestasis).
All patients underwent follow-up for a median duration of 7 years. During this period, 2 patients were lost tofollow-up, 11 remained stable, and 4 experienced deteriorated. None of the children in the study developed livercancer or succumbed to the disease. Apart from cases 5
and 11, who were initially diagnosed with decompensatedcirrhosis, no other child progressed to this condition.
Cases 8 and 11, who underwent liver transplantation,
were monitored for 2 years post-surgery. Presently, bothare administered tacrolimus orally as an anti-rejection
measure. Although their symptoms of jaundice and pruritus resolved post-transplantation, growth and development of case 8 remained below normal levels, while case
11 exhibited postoperative anemia.

Discussion
ALGS, a multisystem disorder affecting multiple organs,
was first reported by Alagille in 1969, with classical diagnostic criteria were established in 1975 [27]. The classicaldiagnostic criteria require histological confirmation ofbile duct paucity and with a minimum of three additional
characteristic symptoms [13, 14, 27]. Due to the stringency of the classical diagnostic criteria, only 12 children
in our study met the criteria. Currently, the diagnosis of
ALGS predominantly relies on revised criteria [15, 16]that emphasize the diagnostic significance of JAG1 genepathogenic variants, enhancing diagnostic efficiency.
Cholestasis is widely regarded as a characteristic symptom in children with ALGS [2, 28–30]. In this study, 94%of patients presented with cholestasis during consultation. This percentage is comparable to the 89% incidenceof cholestasis reported in the King’s College case series[31]. Bile duct paucity or hypoplasia is a key symptomof ALGS. Among the 15 patients who underwent liver
pathology examination in this study, 13 (87%) patients
had bile duct defects of varying degrees, a higher proportion than the 75% incidence of bile duct paucity reported
by King’s College [31]. However, other studies indicatethat the incidence of bile duct paucity in children with

Male
Male
Male
Male
Male
FemaleFemaleFemaleFemaleMale
Female
Male
Male
Male
Male
FemaleFemale

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17

Age of onset Diagnosticage< 1 month
4 years< 1 month
3 years
1 month
10 years
3 months
4 years
120 months 12 years
24 months
3 years< 1 month
10 years< 1 month
1 year3 months
4 years
36 months
3 years
168 months 15 years< 1 month
5 years
36 months
5 years< 1 month
8 years
2 months
6 years
36 months
6 years
3 months
4 years+-

Familyhistory
+
+
+
+
+
+
+
-

Pruritus

+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+

Cholestasis

+
+
N/A
N/A
+
N/A
+
+
N/A
+
+
N/A
-

Posterior
embryotoxon

Characteristic
facies
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+h
+i
+j
+g
+k
+l
+m
+k
+n
+o
+j
+n

+a
+b
+c
+d
+e
N/A
+c
+b
+f
+g
+c
+c
+b
-

Butterfly Cardiac
vertebra abnormality

jaundice; cardiac abnormality
pruritus; jaundice; cardiac abnormality
jaundice; cardiac abnormality
jaundice; cardiac abnormality
jaundice; cardiac abnormality
jaundice
jaundice; cardiac abnormality
pruritus; jaundice; cardiac abnormality
pruritus; jaundice; cardiac abnormality
jaundice
jaundice; cardiac abnormality
pruritus; jaundice; cardiac abnormality
cardiac abnormality
pruritus; jaundicepruritus; jaundicepruritus; jaundice; cardiac abnormality
jaundice

Reason for medical treatment

Last
followup age
16 years
12 years
18 years
12 years
19 years
8 years
16 years
6 years
9 years
9 years
21 years
13 years
6 years
15 years
18 years
15 years
9 years(a) hypoplasia of the left pulmonary artery; (b) pulmonary arterial stenosis accompanied by atrial septal defect or patent foramen ovale; (c) mild regurgitation of the tricuspid valve; (d) perimembranous ventricular septal
defects and pulmonary arterial stenosis; (e) mild regurgitation of the mitral valve; (f) patent ductus arteriosus, atrial septal defect, mild regurgitation of the tricuspid valve, and venous sinus dilation; (g) dilation of thecoronary sinus; (h) at thoracic vertebra 5; (i) at thoracic vertebra 3–8; (j) incomplete butterfly vertebra; k) at thoracic vertebra 6; l) at thoracic vertebra 4, 5, 7 and 10; m) at thoracic vertebra 9; n) at thoracic vertebra 5, 6 and8; o) at lumbar vertebra 5 and sacral vertebra; n) at thoracic vertebra 6–7

Sex

Patient

Table 1 Clinical characteristics of 17 children with ALGS

Yan et al. BMC Pediatrics(2024) 24:532
Page 5 of 12

Yan et al. BMC Pediatrics(2024) 24:532

ALGS can reach up to 85% [32]. Overall, bile duct paucity is the most consistent feature of ALGS [33], and different detection rates may be related to subject age anderrors in liver biopsy. To differentiate biliary atresia (BA),biliary exploration was performed on two children (cases
3 and 7) at 2 months of age. There have been reported
cases where ALGS was erroneously diagnosed as biliaryatresia, ultimately leading to death or liver transplantation following Kasai surgery [34, 35]. Hence, in cases ofsuspected biliary atresia, biliary exploration is crucial to
exclude ALGS.
Characteristic facies is a well-known prominent feature of patients with ALGS, particularly those harboring
pathogenic variants of the JAG1 gene [36, 37]. Characteristic facies can be identified in 80% of children with
ALGS [38], while in this study, 88% of the patients exhibited this typical feature. Prompt identification of suspicious facial features in children is crucial. However,characteristic facies may not be apparent in early infancy[39, 40]. Furthermore, the use of characteristic facies indiagnosis remains controversial due to the subjectivityof facial observation and variations in observer interpretation [39]. Heart disease is the most common extrahepatic manifestation of ALGS, with an overall incidenceof 94% [33]. Among these, the pulmonary artery is themost common site of anomalies, accounting for approximately 76% of all patients with cardiac anomalies [41]. In
this study, approximately 75% of patients exhibited cardiac anomalies, whereas only 25% presented pulmonary
artery anomalies. Although complex cardiac lesions arerecognized as a significant cause of mortality in children
with ALGS [32], none of the children in our follow-up
study succumbed. The prevalence of butterfly vertebrae
in our study was 71%, aligning with previous reportsthat ranged from 33–87% [42]. Most skeletal abnormalities in the studied children were predominantly found in
the thoracic vertebrae, with only case 13 showing lumbar
and sacral vertebrae affected. Posterior embryotoxon is
the most common ocular abnormality in patients with
ALGS, which usually does not affect vision and occurs in
56-95% of ALGS patients [43, 44]. Among the 12 children
who underwent ophthalmic slit lamp examination in thisstudy, 7 were found to have posterior embryotoxon, representing approximately 58% of the examined population.
Genetic testing in this study revealed a pathogenic variant detection rate of 87% for the JAG1 gene, whereas nopathogenic variant was identified in the NOTCH2 gene.
These findings are consistent with the conclusions of previous studies [12]. As an important ligand of the Notch
signaling pathway, changes in the structure and functionof JAG1 protein significantly affect Notch signaling levels [12]. The NOTCH signaling pathway has been foundto be involved in the development of multiple systems,
often manifesting as multi-system symptoms in patients

Page 6 of 12with ALGS [45]. However, genetic testing in this study
yielded negative results for two children. This phenomenon has also been reported in previous studies [27, 46,47], we speculate that it may be related to the fact thatwhole-exome sequencing technology is prone to missdeletions. Additionally, we noticed that four patientsinherited their JAG1 gene pathogenic variants from their“healthy” mothers. These mothers exhibited no overt
clinical symptoms during their visits, and due to limitations, liver pathology examinations were not conductedon these apparently “healthy” mothers. We speculatethat the asymptomatic carriage of JAG1 gene pathogenic
variants may be due to differential expression of the
JAG1 gene in hepatoblasts and portal vein mesenchyme(PVM). Previous studies have suggested that the absenceof Jag1 in hepatoblasts does not affect bile duct development in mice. In addition, the correlation between ALGS
genotype and phenotype remains unclear, and somemodifier genes are thought to impact the phenotype of
patients with ALGS [48].
Ursodeoxycholic acid is currently the first-line therapy for ALGS and has been proven effective in controlling patients’ pruritus and xanthoma formation [49].
Although ursodeoxycholic acid treatment yielded positive therapeutic outcomes for these children, a subset
experienced minimal relief from pruritus. To address
this issue, we added choline amine as adjuvant therapy,
which effectively controlled the children’s pruritus. Clinically, however, liver transplantation remains necessary
for 21-31% of patients due to severe pruritus [50], with
our study observing a 29% rate. While liver transplantation significantly improves patients’ original symptoms,
postoperative complications and the long-term need for
immunosuppressants significantly affect their quality oflife, echoing findings from previous studies [51, 52]. Dueto advancements in treatment modalities and improved
survival rates following liver transplantation (LT), over
90% of children with ALGS now survive into adulthood[2, 29]. By the end of the follow-up, all study patients
had reached adulthood with stable disease conditions.
Hence, it is imperative for adult hepatologists to possessa thorough understanding of the clinical manifestations
and therapeutic approaches associated with ALGS. Suchknowledge is essential to address the evolving healthcaredemands of ALGS patients transitioning from pediatricto adult medical care [2].
This study had several limitations. Firstly, as a retrospective, single-center study, it was constrained by alimited sample size. Secondly, the study’s subjects were
exclusively hospitalized patients with relatively severe
conditions, potentially introducing bias. In future studies, we plan to expand the sample size and include more
outpatient cases. Lastly, all children in this study underwent whole exome sequencing for genetic testing. The

TBil(µmol/L)
16.7
12.6
26.9
15.8
264.5
9.1
92.4
23.8
16.7
8.9
79
28.9
8.6
34.2
12.2
16.4
6.2

DBil
(µmol/L)
5.3
7.1
16
8.2
219.8
4.5
70.7
20
9.5
2.8
57
23.5
2.9
23.5
4.4
8
8.68

ALT
(U/L)
166
203
71
18
171
136
236
99
18
67
117
329
69
29
130
277
19

AST
(U/L)
122
169
228
55
383
116
184
102
47
57
154
118
61
152
116
158
122

ALP
(U/L)
555
922
398
443
184
650
222
501
581
318
154
728
244
650
667
592
535

GGT
(U/L)
266
701
381
374
97
445
201
198
228
213
79
514
74
453
433
438
475

TBA
(µmol/L)
84
41
32
113.9
373
18
214
139
88.9
26
126
108
7
48
41
21
58

LAP
(U/L)
425
800
388
370
64
575
122
417
406
74
117
476
115
288
443
579
402

TC
(mmol/L)
11.25
10.23
7.84
7.88
3.21
8.65
4.09
7.07
7.7
2.43
6.5
11.6
4.26
10.44
7.26
9.69
8.68

TG
(mmol/L)
1.66
1.84
0.81
2.32
1.43
0.49
1.95
2.31
1.62
0.88
1.14
1.21
0.73
1.74
1.13
1.13
1.55

CHE
(U/L)
6751
6336
6055
5377
1609
6507
2157
4479
5760
8653
3670
4548
7462
6387
5595
8233
6520

ALB
(g/L)
43
42
45
37
38
43
29
37
41
45
41
35
41
39
39
42
38

TBil, total bilirubin; DBil, direct bilirubin; ALT, alanine aminotransferase; AST, aspartate aminotransferase; ALP, alkaline phosphatase; GGT, gamma-glutamyl transpeptidase; TBA, total bile acid; LAP, leucine arylamidase; TC,
total cholesterol; TG, triglyceride; CHE, cholinesterase; ALB, albumin; ↑, elevated; ,↓,decreased

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17

Patient

Table 2 Biochemical characteristics of 17 children with ALGS

Yan et al. BMC Pediatrics(2024) 24:532
Page 7 of 12

Yan et al. BMC Pediatrics(2024) 24:532

Page 8 of 12

Fig. 3 The histopathological change of liver biopsy in case 11. A: Liver cell swelling, fibrous tissue proliferation and few bile duct in the portal area (HE,original magnifi cation × 100); B: Few bile duct in the portal area (CK-7/19, original magnifi cation × 100); C: Few bile duct in the portal area (CK-7/19,
original magnifi cation × 200)

Table 3 Pathological results of liver puncture in 15 childrena
with ALGSPatient

Paucity of
intrahepatic
bile duct

Enlarged
Inflammaportal area tion grade

1
2
3
4
6
7
8
10
11
12
13
14
15
16
17

+
+
+
+
+
+
+
+
+
+
+
+

+
+
+
+
+
+
+
+
-

a

G1
G0-1
G1
G0-1
G1
G1
G0-1
G0-1
G2
G0-1
G0-1
G0-1
G1
G0-1
G1

Fibrosis
stage
S1-2
S1
S1
S1-2
S0
S0
S0
S0
S4
S1
S0
S0
S2
S0
S0

2 patients did not receive liver biopsy

limitations of this sequencing technology may result in
missed detections of deletions. Furthermore, it is crucial to acknowledge the challenges posed by the homology in covering exons 1–4 of the NOTCH2 gene, which
may potentially lead to their omission during exome
sequencing.

Conclusion
Cholestasis is the most prevalent characteristic observedin children diagnosed with ALGS. Genetic testing should
be conducted for children presenting with cholestasis,
followed by the application of revised diagnostic criteria for ALGS to minimize misdiagnosis. Pharmacological therapy has proven effective for patients with ALGS,
while liver transplantation may be considered in cases ofsevere pruritus.

Yan et al. BMC Pediatrics(2024) 24:532

Page 9 of 12

Table 4 Genetic traits of children with Alagille syndrome
Patient

cDNA Variant

Exon/Intron

Mutation typec.232_233dup

Amino acidchangep.L79Afs*83

1

Exon2

Frameshift2c.439 + 1G > A?

Intron3

Canonical-splice -Unknown3c.2323G > T

p.E775*

Exon18

Nonsense

EGF

Unknown

4c.3000delExon24

Frameshift-

De novo

5c.550 C > Tp.
I1000Mfs*36
p.R184C

Exon4

Missense

DSL

De novo6c.1308 C > A

p.C436*

Exon10Nonsense

EGF_CA

Mother7c.3002_3003delp.
Exon24
A1001Vfs*10

Frameshift-

De novo

8c.548T > A

p.I183N

Exon4

Missense

DSL

Mother9c.2122_2125del

Exon17

Frameshift-

De novo

10c.1485_1486delp.
Q708Vfs*34
p.C496Ffs*9

Exon12

Frameshift

EGF_CA

Mother13

chr20:10018942– ?
17,550,915-

Deletion-

Unknown

14c.162delExon2

Frameshift

MNNL

Mother16c.100 C > T

Exon2

Nonsense

MNNL

De novop.
C54Afs*106
p.Q34*

ProteinRegionMNNLParental
OriginUnknown

Classification according to
ACMG [26, 53]
Pathogenic(PVS1 + PM2_Supporting + PP4)
Pathogenic(PVS1 + PS4 + PM2_Supporting)
Pathogenic(PVS1 + PS4_Supporting + PM2_
Supporting)
Pathogenic(PVS1 + PM2_Supporting + PP4)
Pathogenic(PP3_Strong + PM2_Supporting + PS2_VeryStrong)
Pathogenic(PVS1 + PM2_Supporting + PS4_
Supporting)
Pathogenic(PVS1 + PM2_Supporting + PS4_
Supporting)Likely pathogenic(PP3_Strong + PM2_Supporting + PP2 + PP4)
Pathogenic(PVS1 + PS4 + PM2_Supporting)
Pathogenic(PVS1 + PS4_Moderate + PM2_
Supporting)
Pathogenic(Section1A + 2 A + 3 A + 5 F = 1 > 0.99)
Pathogenic(PVS1 + PM2_Supporting + PP4)
Pathogenic

Reports
This
study
[3,
54–58]
[59]

This
study
[60,
61]
[62]

[61]

This
study
[8,
62–66][61,
67–69]
This
study
[59]
[59]

MNNL – N-terminus of Notch ligand, EGF – epidermal growth factor repeats domain, DSL – Delta serrate ligand, EGF _CA – calcium-binding EGF-like domain, CR–cysteine-rich region, CM-TM – region between CR and TM, TM – transmembrane domain

Yan et al. BMC Pediatrics(2024) 24:532

Page 10 of 12

Fig. 4 The protein structure of mutation p.I183N was shown in red (PDBID:4CC0)
Abbreviations
ALGS	Alagille Syndrome
JAG1	Jagged Canonical Notch Ligand 1
NOTCH2	Notch Homolog 2
GGT	Gamma-Glutamyl Transpeptidase
CT	Computed Tomography
MRI	Magnetic Resonance Imaging
hg19	human reference genome version 19
BWA	Burrows-Wheeler Alignment
GATK	Genome Analysis Toolkit
SNPs	Single-Nucleotide Polymorphisms
ANNOVAR	ANNOtation VARiants
SIFT	Sorting Intolerant From Tolerant
SNVs	Single-Nucleotide Variants
ACMG	American College of Medical Genetics and Genomics
VUS	Variants of Unknown Clinical Significance
WES	Whole-Exome Sequencing
PCR	Polymerase Chain Reaction
AST	Aspartate Transaminase
LAP	Leucine Aminopeptidase
TBA	Total Biliary Acid
ALT	Alanine AminotransferaseTC	Total Cholesterol
TG	Triglycerides
TBil	Total Bilirubin
DBil	Direct Bilirubin
ALP	Alkaline Phosphatase

Supplementary Information

The online version contains supplementary material available at https://doi.
org/10.1186/s12887-024-04973-y.
Supplementary Material 1

Acknowledgements
We are particularly grateful to all the people who have given us help on our
article.
Author contributions
MZ, JGY and YZH conceived the idea and conceptualised the study. JGY andYZH collected data.JGY, YZH, ZQX, YD, FCW, YJG, LLC and DNF analyzed thedata. JGY and YZH wrote the main manuscript text and repared all figures. MZ
reviewed the manuscript. All authors reviewed the manuscript.
Funding
The capital health development project 2022-1-2182.
Data availability
All data generated or analyzed during this study are included in this article.
Further enquiries can be directed to the corresponding author.

Declarations
Ethics approval and consent to participate
The study was conducted in accordance with the Declaration of Helsinki(as was revised in 2013). The study was approved by Ethics Committee of
The Fifth Medical Center of Chinese PLA General Hospital. We obtained
written informed consent from all subjects and/or their legal guardian(s) for
publication of identifying information/images.
Consent to publish
Informed consent from all subjects and/or their legal guardian(s) for
publication of identifying information/images was obtained.
Competing interests
The authors declare no competing interests.
Received: 29 October 2023 / Accepted: 25 July 2024

Supplementary Material 2
Supplementary Material 3
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