Journal of Pediatric Cardiology and Cardiac Surgery 3(1): 56‒60 (2019)

Case Report

Only Characteristics Vascular Lesions of Williams-Beuren
Syndrome in a Girl with a Novel Nonsense ELN Mutation
Shintaro Terashita, MD1, 2), Hideyuki Nakaoka, MD, PhD1),
Keijiro Ibuki, MD, PhD1), Sayaka Ozawa, MD, PhD1), Keiichi Hirono, MD, PhD1),
Yuichi Adachi, MD, PhD1), Shuhei Fujita, MD, PhD3),
Toshio Nakanishi, MD, PhD4), and Fukiko Ichida, MD, PhD1)
1) Department of Pediatrics, University of Toyama, Toyama, Japan

2) Department of Endocrinology and Metabolism, National Center for Child Health and Development, Tokyo, Japan
3) Department of Pediatrics, Toyama Prefectural Central Hospital, Toyama, Japan

4) Department of Pediatric Cardiology, Tokyo Womenʼs Medical University, Tokyo, Japan

Williams-Beuren syndrome (WBS) is caused by microdeletions of 7q11.23, including the ELN gene, and thecharacteristic vascular lesions include supravalvular aortic stenosis (SVAS) and peripheral pulmonary arterystenosis (PPS). We identified a patient who has the characteristic cardiovascular lesions of WBS but does nothave the 7q11.23 deletion: analysis of ELN identified a nonsense mutation. This case is a baby girl, whose cardiovascular abnormalities were not identified during fetal life. She was admitted with systemic cyanosis after birth,and was diagnosed with SVAS and supravalvular pulmonary stenosis (SVPS). At 10 months of age she underwent
cardiac catheterization and confirmed SVAS, which was accompanied by a thin ascending aorta, PPS narrowing
from hilar, and SVPS. Due to high blood pressure and hyperreninemia, she was diagnosed with renal vascular
hypertension caused by bilateral renal artery stenosis identified on MDCT and began an oral carvedilol regimen.
Mental retardation and malformations associated with WBS were not observed and a FISH analysis excluded a
microdeletion encompassing ELN. Since mutations in ELN have been identified in cases of isolated SVAS it wasscreened and a novel nonsense mutation in Exon 24 was identified. Thus, the cardiovascular lesions were considered to be caused by elastin deficiency due to this ELN mutation. We suggest that if a patient has the characteristic
cardiovascular lesions of WBS, but is FISH negative, then ELN should be screened for mutations.

Keywords: Williams-Beuren syndrome, ELN gene, supravalvular aortic stenosis, peripheral pulmonary
artery stenosis, supravalvular pulmonary stenosis

Introduction
Williams-Beuren syndrome (WBS) is contiguous
gene syndrome caused by microdeletions of 7q11.23 andfeatures cardiovascular lesions (supravalvular aortic stenosis [SVAS] and peripheral pulmonary artery stenosis[PPS]), distinctive facies (thick medial eyebrow, blepharophimosis, epicanthus, puﬀy eye, short and turned-up
nose, long philtrum, opened thick lips) and specific cog-nitive profiles (specialty of the expressed languages, recognition of faces and music and poor visuospatial perception). The frequency of WBS has been estimated tobe 1: 7500‒20000, no gender diﬀerences, and the majority of them is sporadic. The prognosis of WBS without
cardiovascular lesions is relatively favorable.1) The
chromosome 7q11.23 includes several genes, ELN andGTF2I (Fig. 1), and ELN is responsible for expressions ofthe elastin which is the main component of elastic fibers.

Received: November 6, 2018; Accepted: January 4, 2019
Corresponding author: Shintaro Terashita, MD, Department of Pediatrics, University of Toyama, 2630 Sugitani, Toyama-shi, Toyama
930-0194, Japan
E-mail: sterashita@ped-toyama.com
Originally published in Journal of Japanese Pediatric Society, Vol. 121 (2017) No. 7, pp. 1179‒1183
doi: 10.24509/jpccs.190110© 2019 Japanese Society of Pediatric Cardiology and Cardiac Surgery

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Fig. 1 Schematic diagram at 7q11.23 region
ELN is encoded at chromosome 7q11.23 region, and the LIMK1 and GTF2I are contiguous.

The elastin is comprised of systemic connective tissue,
aorta, lungs, skins and ligaments, and the abnormal
expressions of elastin according to ELN mutation induce
various symptoms, example for vascular wall thickening.
The past reports of ELN failure are accompanied with
WBS and SVAS (familial and sporadic).
Here, we present the case of a girl with a nonsense
mutation in ELN that has never been reported before,
while she has only characteristics cardiovascular lesionsof WBS and fluorescence in situ hybridization (FISH)
negative.

Case
A baby girl was not pointed out fetal abnormality andhad nonconsanguineous healthy parents, two sisters andone brother. She was born at 40 weeks of gestation byvaginal delivery at previous hospital. After birth, she wassystemic cyanosis and crying weakly, so needed manual
ventilation (Apgar score: 6‒8). She was pointed out systolic murmur and transferred our hospital.
Her clinical findings was as follows; body temperature
was 37.1°C, pulse rate was 104 beats per minute, percutaneous saturation was 99‒100% (oxygen flow 1 L per minute), blood pressure was 92/50 mmHg, height was 48 cm(−0.91 SD), body weight was 3,374 g (+0.61 SD) andhead circumference was 33 cm (−0.39 SD). Her large
fontanel was 2 cm and flat. She did not have cyanosis anddistinctive facies. Her respiratory sounds were good, andsystolic murmur (Levine III/VI) at three left sternal bone
were noticed. Her abdomen was soft and flat, and goodbowel sounds without hepatosplenomegaly, tumor andabdominal vascular sounds. An edema, joint contracture and skin lesion was not noticed. Laboratory routine
investigations in blood were normal. A cardiothoracic
rate was 0.66 without pulmonary lesions by X-rayinvestigation. ECG showed the right axis deviation andR-wave progression in V3 induction. 2D echo showed aright ventricular hyperplasia, a tricuspid regurgitation
and a pressure gradient between right atrium and ventricle. A diameter of supravalvular pulmonary artery was
3.2 mm with a pressure gradient between the stenosis. A
bifurcation of pulmonary trunk stenosis made prominent mosaic blood flow in peripheral pulmonary arteries. An Aortic valve was tricuspid without regurgitation.
A stenosis of sinotubular junction, 3.9 mm (−2.27 SD),
2.7 meter per second and estimated 30 mmHg pressure
gradient, made a mosaic blood flow after the stenosis. In
conclusion, we diagnosed her SVAS, PPS and supravalvular pulmonary stenosis.
Her state was stable without particular interventions until echocardiography showed the signs ofright heart failure at six days after birth, and we began
diuretics (furosemide [1 mg/kg/day] and aldactone[1 mg/kg/day]). She was discharged at twenty days after
birth since SVAS and PPS did not proceed. She wasa normal psychomotor development, smiling at twomonths old, head controlling at four months old, sitting
at seven months old and crawling at nine months old.
The distinctive facies and the undeveloped recognition
were not seen in follow-up periods. At ten months old,
she was hospitalized and received cardiac catheterization for consideration of treatment policy. Cardiac cath-© 2019 Japanese Society of Pediatric Cardiology and Cardiac Surgery

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Table 1 Cardiac catheterization at 10 months
Site
RV
LV
aAomain PA
rt. PA
lt. PA
Wedge mean

Pressure (mmHg)
78/4
148/10112/48 (76)74/10 (32)
17/6 (8)16/10 (11)
R=8

L=8RV-MPA=70 mmHg
lt.PA-main PA=59 mmHg
rt.PA prox-main PA=40 mmHg
rt.PA prox-RPA dist=17 mmHg
aAo: ascending aorta, LV: left ventricle, PA: pulmonary
artery, RV: right ventricle

eterization revealed that the pressure gradient was rightatrium-right ventricle, bilateral peripheral pulmonary
arteries-main pulmonary artery and left ventricle-ascending aorta. Estimated pressure gradient between left
ventricle and ascending aorta was 40 mmHg and cardiac
contractility was suﬃcient (Table 1), so we decided tomanage her without surgical interventions. For hypertension, we performed Multi Detector-row Computed
Tomography and discovered bilateral renal arterystenosis (Fig. 2). She had high renin/angiotensin ratio(plasma renin activity was 59.5 ng/mL/hr [referencerange; 0.2‒2.7 ng/mL/hr] and plasma aldosterone concentration was 128 ng/dL [reference range; 2‒13 ng/dL]),and we diagnosed her renovascular hypertension andstarted carvedilol.
She is now one and a half years old, and height is80.6 cm (+0.44 SD), body weight is 9.1 kg (−0.78 SD)
and head circumference was 44.8 cm (−1.13 SD). She
has good cardiac function without hypertension andis not psychomotor retardation (movement; 94, hand
movement; 108, basic habit; 108, interpersonal relation;
108, speech; 94 and language understanding; 94 by using
Enjoji Scale of Infant Analytical development).
Molecular Genetic StudyAs SVAS and PPS were the characteristic cardiovascular lesions of WBS, we tried to detect a deletion at chromosome 7q11.23 by FISH (Elastin probe from Vysis),but no deletion was detected. So, we obtained informed
consent from her parents and analyzed ELN which
was responsible for cardiovascular lesions of WBS. We
got approval for gene analysis from Toyama University Ethics Committee. We amplified the Exon coding
region and the contiguous region including the introns
J Pediatr Cardiol Card Surg Vol. 3, No. 1 (2019)

Fig. 2 Multi detector-row computed tomography
Bilateral renal artery stenosis is observed (arrow).

for ELN by using the primer which was obtained fromher peripheral blood lymphocyte genome DNA (weare ready to disclose the primer information when youneed). We purified the amprified products by QIAquick
polymerase chain reaction (PCR) purification method(QIAGEN, Hilden, Germany) and analyzed mutations
by direct-sequencing using ABI 3130xl DNA Analyzer(Applied Biosystems, Foster City, CA, USA). As a result,we identified the nonsense mutation in heterozygoteof ELN [c.1615C>T (p.Gln539X)] (Fig. 3). Using
direct-sequencing, we also analyzed PTPN11, RAF1,SOS1, Shoc2, PKA and PKC, which were responsible forNoonan syndrome having PS with high probability, butno mutations were detected. We have not analyzed themutations of her parents and brothers yet.

Discussion
WBS is a contiguous gene syndrome according to apartial deletion at chromosome 7q11.23. A cardiovascular lesions of WBS were SVAS, PPS, aortic hypoplasia,
coarctation of aorta and mitral valve prolapse.2) SVAS
and PPS are especially characteristic for WBS. As sporadic SVAS is rare, estimated to be 5‒7: 100000, so weneed to take WBS into account in case of diagnosing
SVAS.3) ELN is identified as a responsible gene for cardiovascular lesions of WBS.
ELN contribute to expression of the elastin. The elastin
is a main component of elastic fiber and is widely distributed in artery, especially in a root of aorta, skin andlungs. It is advocated that decreasing of the elastin leadto increasing of the collagen in tunica media of arteryand vessel wall becomes thicken and harden. In ELN

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Fig. 3 Schematic diagram of ELN [Quoted from reference 9]
Posted on previously reported mutations. Exon 16 and Exon 24 include elastin binding protein region.

gene knockout mice, it was reported that a homozygous
mouse died in a few days according to aortic obstruction
with hypertrophy of smooth muscle and a heterozygous
mouse had a half expression of an elastin protein andmessenger RNA.4) A point mutation of ELN can occur
cardiovascular lesions.5) Frangiskakis and Tassabehjireport the plural familial SVAS families with ELN mutation, so it is considered that ELN is also responsible genefor cardiovascular lesions of familial SVAS.6, 7) Cardiovascular lesions can occur not only for a great mutation,
including nonsense mutation and frameshift mutation,
but also for a missense mutation, and the expression
pattern is variable.5, 7‒9)
We present the case with a nonsense mutation inheterozygote of ELN [c.1615C>T (p.Gln539X)], thathas never been reported before. Among ELN mutations,many cases with missense mutation have relatively mild
cardiovascular lesions and many cases with nonsense
mutation or frameshift mutation have severe cardiovascular lesions. In addition, since Exon 16 and Exon
24 contain elastin binding protein region and severe
cardiovascular lesions (SVAS, PPS, aortic hypoplasia)
are observed in cases with Exon 16 mutation (frameshift), it is suggested that a deletion at Exon 16 or Exon
24 tends to cause more severe cardiovascular lesions. In
this case, in addition to SVAS, PPS and supravalvularpulmonary stenosis, bilateral renal artery stenosis was
also observed, and renal artery stenosis is rare in thepast reports. A nonsense-mediated RNA decay is also
considered for nonsense mutation, but in this case,because of nonsense mutation of Exon 24 which has animportant role among ELN genes, it is considered that
serious quantitative or qualitative change of elastin werecaused and cardiovascular lesions characteristic of WBS
and other widespread cardiovascular lesions developedby this ELN mutation.9)
In this case, the limitations is as follows; the follow-up
period is short in one year, so it is insuﬃcient to examine other lesions except for cardiovascular lesions anddevelopment. Second, it is not directly proven that ELN
mutation is causing functional abnormality of elastin.

Conclusion
We presented the case having characteristics cardiovascular lesions of WBS with a nonsense mutation in
ELN that has never been reported before. In cases with© 2019 Japanese Society of Pediatric Cardiology and Cardiac Surgery

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characteristic cardiovascular lesions of WBS, we need toconsider the case having only ELN mutation with FISH
negative and understand for pathological condition ofcardiovascular lesion and extracardial lesion.
Conﬂicts of Interest
The authors declare no conflict of interest.
Authorship Contribution
S.T. designed and wrote the paper. S.T., H.N., K.I., S.O.,
K.H. and Y.A. practiced medicine. S.H. transferred thepatient to our hospital and provided the information atbirth. T.N. performed gene analysis. F.I. was responsible forthe paper and gave a critical review on intellectual content.

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