TaoMedAI/RareMedData huggingface dataset:
Juvenile absence epilepsy (ORPHA:1941)
Juvenile absence epilepsy (JAE) is a genetic epilepsy with onset occurring around puberty. JAE is characterized by sporadic occurrence of absence seizures, frequently associated with a long-life prevalence of generalized tonic-clonic seizures (GTCS) and sporadic myoclonic jerks.
Epidemiology
The incidence of JAE is still unknown but it accounts for approximately 2-3% of patients with adult epilepsy in general, and about 8-10% of patients with genetic generalized epilepsy (GGE). No sex predominance has been observed.
Clinical description
JAE is characterized by sporadic occurrence of absence seizures (only one or a few absences daily; 100% of cases), frequently associated with a long-life prevalence of generalized tonic-clonic seizures (GTCS; 80%) and sporadic myoclonic jerks (20%). The seizures onset is typically between 9 and 13 years of age and it manifests as a ''staring spell'' that can be accompanied by atonic postures such as drooping of the head and/or automatisms such as lip smacking. GTCS and myoclonic seizures often occur 1-10 years after the absence seizure onset. Patients with JAE usually develop normally, although uncontrolled absence seizures may have an impact on their ability to learn at school.
Etiology
The exact etiology of JAE is still elusive. However, genetic mutations for voltage-gated sodium channels (CACNB4 gene (2q22-q23)), potassium channels (CLCN2 gene (3q27.1)), and EFHC1 (6p12.3) may be involved in a subset of patients. Moreover, different mutations have been found in genes for GABA receptors (ligand ion channels), specifically in the GABRA1 gene (5q34).
Diagnostic methods
Diagnosis relies on the clinical features and on electroencephalogram (EEG) recorded awake and during sleep, that displays a generalized 3-4 Hz spike-and-slow-wave complexes.
Differential diagnosis
Differential diagnosis includes childhood absence epilepsy, juvenile myoclonic epilepsy, Jeavons syndrome (see these terms).
Genetic counseling
The transmission is still unknown although an increased risk for first degree related parents to develop JME may exist.
Management and treatment
The antiepileptic drugs of choice are valproic acid (VPA) and lamotrigine (LTG). In cases where VPA deals with only partial seizure control, add-on of LTG (GTCS) or ethosuximide (absence seizures) can be beneficial.
Prognosis
Prognosis of JAE is usually favorable with good therapy responsiveness. Generally, seizure freedom can be achieved with antiepileptic medication in 62-84% of all patients with JAE. However, the occurrence of GTCS predicts a worse prognosis.

                            Last update: 
                            November 2015


                            - Expert reviewer(s): 
                            Dr Gabrielle RUDOLF
Juvenile amyotrophic lateral sclerosis (ORPHA:300605)
Juvenile amyotrophic lateral sclerosis (JALS) is a very rare severe motor neuron disease characterized by progressive upper and lower motor neuron degeneration causing facial spasticity, dysarthria, and gait disorders with onset before 25 years of age.
Epidemiology
The prevalence and incidence of JALS are not known. A small number of cases have been reported to date. The disorder has been described in various ethnic groups.
Clinical description
Onset is during childhood with a mean age of 6.5 years and a reported range of 3 to 20 years. Patients then develop motor neuron degeneration leading to facial muscle spasticity, spastic dysarthria, and spastic gait. Some patients are reported to have uncontrolled laughter and weeping (pseudobulbar syndrome). Mild atrophy of the legs and hands are observed in some cases. Bladder dysfunction and sensory disturbances are also found. The disease is usually slowly progressive and some patients have been reported to have become bedridden by 12 to 50 years of age.
Etiology
Mutations in the following genes have been found in patients presenting with JALS: ALS2 (2q33-q35), and rarely SIGMAR1 (9p13.3), SPG11 (15q13-q15) and FUS (16p11.2). Mutations in the latter gene are sporadic and appear to be associated with a severe and aggressive course.
Diagnostic methods
Diagnosis is based on the clinical findings. Motor evoked potential studies show absent or reduced action potentials, electromyography demonstrates signs of denervation, while nerve conduction velocities are normal. Magnetic resonance imaging (MRI) scans of the brain and spinal cord are normal.
Differential diagnosis
Differential diagnoses include juvenile primary lateral sclerosis and, to a lesser extent, infantile-onset ascending hereditary spastic paralysis (see these terms).
Genetic counseling
Cases related to the ALS2 and SIGMAR1 genes have an autosomal recessive pattern of inheritance. Genetic counseling should be provided to affected families.
Management and treatment
There is currently no specific treatment. Management primarily involves physical and occupational therapy to promote mobility and independence.
Prognosis
Prognosis is guarded and quality of life severely affected by the clinical manifestations of the disease.

                            Last update: 
                            February 2014


                            - Expert reviewer(s): 
                            Pr Enrico BERTINI
Juvenile cataract-microcornea-renal glucosuria syndrome (ORPHA:247794)
A rare autosomal dominant association characterized clinically by juvenile cataract associated with bilateral microcornea, and renal glucosuria without other renal tubular defects.
Juvenile glaucoma (ORPHA:98977)
A rare primary early-onset glaucoma characterized by early onset, severe elevation of intra ocular pressure of rapid progression, leading to optic nerve excavation and, when untreated, substantial visual impairment.
Epidemiology
The disorder is estimated to occur in 0,32/100 000 individuals before the age of 20 years.
Clinical description
Juvenile glaucoma (JG) typically presents between the ages of 5 to 18 years, but it can appear later. Patients are initially asymptomatic and are often discovered incidentally on a routine examination. JG is generally bilateral; there can be a marked asymmetry between the two eyes. The intraocular pressure increases progressively leading to optic nerve excavation and eventually, substantial visual impairment and field loss.
Etiology
JG is caused by impaired outflow of aqueous humor through the trabecular meshwork and into the Schlemm canal. Mutation in MYOC (1q23-q24) genes have been found in patients with JG. MYOC gene codes for the glycoprotein myocilin that is found in the trabecular meshwork and ocular tissue and mutations are disease-causing.
Diagnostic methods
The diagnosis is suspected with the presence of clinical features such as increased intraocular pressure and optic nerve excavation. On gonioscopy the angle appears normal. Typical features of primary congenital glaucoma such as corneal edema and Haab's striae are not present. The refraction test reveals myopia. Typical glaucomatous field defects can be documented. Optic nerve head shows glaucomatous optic neuropathy.
Differential diagnosis
Differential diagnoses include other forms of open angle glaucoma that can occur at any age, late recognized congenital glaucoma, steroid induced glaucoma, traumatic glaucoma and inflammatory glaucoma.
Genetic counseling
Transmission is autosomal dominant with high penetrance. Genetic testing can be used to identify family members at risk of developing JG. Genetic counseling should be proposed to individuals having the disease-causing mutation informing them that there is 50% risk of passing the mutation to offspring.
Management and treatment
Medical therapy (carbonic anhydrase inhibitors, beta blockers, prostaglandin analogues) is often useful in the treatment of JG. When the condition becomes unresponsive to medications, angle surgery (goniotomy, trabeculotomy), filtration surgery (trabeculectomy), LASER treatment (angle laser surgery or cyclodiode laser therapy) and/or aqueous shunt devices can be considered.
Prognosis
Prognosis is good in patients diagnosed and treated early. Without treatment, the evolution towards blindness is possible.

                            Last update: 
                            December 2019


                            - Expert reviewer(s): 
                            Dr Pascal DUREAU  - Dr Emmanuel MARCIANO
Juvenile hyaline fibromatosis (ORPHA:2028)
A rare hyaline fibromatosis syndrome characterized by papulo-nodular skin lesions (especially around the head and neck), soft tissue masses, gingival hypertrophy, joint contractures, and osteolytic bone lesions in variable degrees. Joint contractures may cripple patients and delay normal motor development if occuring in infancy. Severe gingival hyperplasia can interfere with eating and delay dentition. Histopathology analysis of involved tissues reveals cords of spindle-shaped cells embedded in an amorphous, hyaline material.
Juvenile idiopathic arthritis (ORPHA:92)
A rare, heterogeneous group of rheumatologic diseases characterized by arthritis which has an onset before 16 years of age, persists for more than 6 weeks, and is of unknown origin.
Juvenile myelomonocytic leukemia (ORPHA:86834)
A rare myelodysplastic/myeloproliferative neoplasm characterized by a proliferation primarily of granulocytic and monocytic lineages with infiltration of the liver and spleen, among other organs. Blasts and promonocytes account for less than 20% of white blood cells in peripheral blood and bone marrow. Erythroid and megakaryocytic abnormalities are often present. BCR-ABL1 fusion is absent, while somatic mutations in genes of the RAS pathway or monosomy 7 may be found. The condition may also occur in the context of neurofibromatosis type 1 or Noonan syndrome-like disorder. Children of less than three years are predominantly affected, with a clear male preponderance. Most patients present with constitutional symptoms, signs of infection, and hepatosplenomegaly.
Juvenile myoclonic epilepsy (ORPHA:307)
Juvenile myoclonic epilepsy is the most common hereditary idiopathic generalized epilepsy syndrome and is characterized by myoclonic jerks of the upper limbs on awakening, generalized tonic-clonic seizures manifesting during adolescence and triggered by sleep deprivation, alcohol intake, and cognitive activities, and typical absence seizures (30% of cases).
Juvenile nasopharyngeal angiofibroma (ORPHA:289596)
Juvenile nasopharyngeal angiofibroma (JNA) is a rare and benign but locally aggressive fibrovascular tumor arising from the posterolateral wall of the nasopharynx, which affects mainly young and adolescent males (onset usually occurring between 7-19 years of age) and that presents as a mass in the nasopharynx and nasal cavity, leading to manifestations such as nasal obstruction, epistaxis, profound facial swelling, proptosis or diplopia. Although slowly progressive, it has a high rate of recurrence and sometimes invades adjacent structures.
Juvenile nephropathic cystinosis (ORPHA:411634)
A subtype of cystinosis characterized by an accumulation of cystine in different organs and tissues, particularly in the kidneys and eyes, and that clinically manifests between childhood and adolescence with a slowly progressive proximal tubulopathy and/or proteinuria, and photophobia. Extra-renal manifestations (e.g. hypothyroidism, insulin-dependent diabetes, hepatosplenomegaly, muscular and cerebral involvement) are less severe than in the infantile form of the disease.
Juvenile overlap myositis (ORPHA:329894)
A rare juvenile idiopathic inflammatory myopathy characterized by the association of inflammatory myositis (manifesting with acral erythema, progressive weakness of the limbs, pain, general fatigue, moodiness or crankiness) with clinical and/or laboratory features of other autoimmune diseases (e.g. systemic lupus erythematosus, localized scleroderma, diabetes). Cardiac involvement has been reported in some patients.
Juvenile Paget disease (ORPHA:2801)
Juvenile Paget disease is a very rare form of Paget disease of the bone characterized by a general increase in bone turnover with increased bone resorption and deposition, resulting in cortical and trabecular thickening, and clinically presenting as progressive skeletal deformities, growth impairment, fractures, vertebral collapse, skull enlargement and sensorineural hearing loss.
Juvenile polymyositis (ORPHA:93568)
A rare type of juvenile idiopathic inflammatory myopathy (IIM) characterized by an onset before 18 years of age of chronic skeletal muscle inflammation, manifesting as progressive, proximal and distal muscle weakness and atrophy.
Juvenile polyposis of infancy (ORPHA:79076)
Juvenile polyposis of infancy (JPI) is the most severe form of juvenile gastrointestinal polyposis (see this term) and is characterized by pancolonic hamartomatous polyposis from stomach to rectum, diagnosed in the first two years of life.
Epidemiology
Prevalence is unknown but only 11 cases have been described in the literature so far.
Clinical description
The digestive phenotype is severe and life-threatening, with gastrointestinal bleeding, diarrhea, inanition and exudative enteropathy. Early death has been reported and the risk of cancer in surviving children has not yet been clearly established. Signs of the Cowden or Bannayan-Riley-Ruvalcaba (BRRS) syndromes (see these terms) such as macrocephaly, lipomas, and hemangioblastomas can be observed. Dysmorphic signs, such as a large forehead, hypertelorism, down-slanting palpebral fissures, a flat nasal bridge, low-set ears, and a small mouth and chin, have also been described. Mild intellectual deficit has been reported in some cases. Recently, a less severe form of JPI has been described in several patients with early-onset gastrointestinal tract juvenile polyps but with a mild digestive phenotype.
Etiology
The majority of cases are caused by a large deletion in the chromosome 10q23 region, encompassing the PTEN and BMPR1A genes. The hypothesis is that the severe digestive phenotype results from a cooperative effect of the deletion of each gene. However, this hypothesis is under debate as the patients with the mild digestive phenotype were also found to harbor a deletion of the PTEN and BMPR1A genes.
Diagnostic methods
Diagnosis may be suspected on the basis of the clinical picture and digestive endoscopy investigation but is confirmed by detection of the 10q23 deletion. This deletion is rarely detected through karyotype analysis, and FISH or Array-CGH, followed by semiquantitative PCR methods (QMPSF, MLPA, MP/LC), are required to define the length and the location of the deletions.
Differential diagnosis
The differential diagnosis should include the allelic disorders Cowden syndrome and Bannayan-Riley-Ruvalcaba syndrome, which are caused by mutations in the PTEN gene, as well as familial adenomatous polyposis and Peutz-Jeghers syndrome (see these terms).
Genetic counseling
JPI appears to be sporadic.
Management and treatment
Management revolves around colonoscopy with endoscopic polypectomy. Early endoscopic polypectomy may reduce morbidity by reducing the risk of the cancer, bleeding, or intestinal obstruction.
Prognosis
However, as JPI is life-threatening and colectomy is generally necessary in infancy, the prognosis during infancy is severe and the survival rate is generally low. The prognosis for surviving children depends on the risk of gastrointestinal tract cancer.

                            Last update: 
                            December 2008


                            - Expert reviewer(s): 
                            Dr Capucine DELNATTE  - Pr Damien SANLAVILLE  - Pr Dominique STOPPA-LYONNET
Juvenile primary lateral sclerosis (ORPHA:247604)
A very rare motor neuron disease characterized by progressive upper motor neuron dysfunction leading to loss of the ability to walk with wheelchair dependence, and subsequently, loss of motor speech production.
Epidemiology
The prevalence and incidence of JPLS are not known. A very small number of cases have been reported to date with this condition. The disorder has been described in various ethnic groups.
Clinical description
Affected patients are usually normal at birth and have normal early development. During the second year of life, they lose the ability to walk (some patients never walk due to early severe spasticity) and then develop slowly progressive upper motor neuron disorders including pseudobulbar palsy and spastic quadriplegia. Other signs include clumsiness, muscle weakness and balance difficulties. Patients generally become wheelchair dependent by adolescence. Between 2 and 10 years of age, motor speech production is lost causing dysarthria, dysphagia and drooling. Cognitive function is generally not affected.
Etiology
Mutations in the ALS2 gene (2q33-q35) encoding alsin, a protein that is abundant in motor neurons, and less commonly mutations in the ERLIN2 gene (8p11.2) have been reported.
Diagnostic methods
Diagnosis is based on the characteristic clinical signs and can be confirmed by molecular genetic testing. Electromyography, nerve conduction velocities, visual evoked potentials, and brain stem auditory evoked potentials are all normal, while transcranial magnetic stimulation shows no motor evoked potentials. Computed tomography (CT) and magnetic resonance imaging (MRI) scans of the brain and spinal cord are normal.
Differential diagnosis
Differential diagnoses include the allelic disorders juvenile amyotrophic lateral sclerosis and infantile-onset ascending hereditary spastic paralysis (see these terms).
Antenatal diagnosis
Prenatal diagnosis for at-risk pregnancies is possible if the disease-causing mutations have been identified in the family.
Genetic counseling
JPLS is inherited in an autosomal recessive manner. The parents of an affected individual are obligate heterozygotes and are therefore asymptomatic carriers. Genetic counseling should be provided to affected families.
Management and treatment
Management primarily involves physical and occupational therapy to promote mobility and independence.
Prognosis
The prognosis is guarded, with the clinical signs having a major impact on quality of life.

                            Last update: 
                            February 2014


                            - Expert reviewer(s): 
                            Pr Enrico BERTINI
Juvenile temporal arteritis (ORPHA:26137)
A rare vasculitis characterized by mostly unilateral inflammation of the temporal artery affecting patients up to fifty years of age. Patients typically present with a lump in the temporal region or a prominent temporal artery and often have headaches. Males are more frequently affected than females, and major systemic symptoms, ocular complications, and a biological inflammatory syndrome are usually absent, although peripheral blood eosinophilia may be seen. Histopathological analysis shows arteritis predominantly of the intima with possible extension to the perivascular tissue. The presence of granuloma, giant cells or fibrinoid necrosis is rare. Clinical relapses after one episode are uncommon.
Juvenile xanthogranuloma (ORPHA:158000)
Juvenile xanthogranuloma is the most common type of non-Langerhans cell histiocytosis (see this term) characterized by the occurrence of one or more reddish or yellowish self-limiting and benign papules or nodules of several millimeters in diameter, usually appearing on the head and neck (but sometimes on the extremities and trunk) during the first year of life (or rarely in adulthood) and usually regressing spontaneously. Extracutaneous involvement has also been reported, involving most commonly the eye (uveal tract) but with other locations including the central nervous system, lung, liver, bones and endocrine glands, and may be associated with considerable morbidity.
Juvenile-onset diabetes mellitus-central and peripheral neurodegeneration syndrome (ORPHA:445062)
A rare genetic disease characterized by juvenile-onset insulin-dependent diabetes mellitus associated with central and peripheral nervous system abnormalities with variable onset between infancy and adolescence. Neurological manifestations include combined cerebellar and afferent ataxia, sensorineural hearing loss, pyramidal tract signs, and demyelinating sensorimotor peripheral neuropathy. Hypothyroidism has been reported in some patients. Brain imaging may show generalized cerebral atrophy.
Juxtaposition of the atrial appendages (ORPHA:99100)
Juxtaposition of the atrial appendages is a rare atrial appendage anomaly when both appendages are located on the left or the right side of the great arteries. It is asymptomatic and is usually diagnosed incidentally, but is frequently associated with other congenital heart diseases.
Kagami-Ogata syndrome (ORPHA:254519)
Kagami-Ogata syndrome is a rare genetic disease characterized by polyhydramnios (mostly due to placentomegaly), fetal macrosomia, abdominal wall defects, skeletal abnormalities (including bell-shaped thorax, coat-hanger appearance of the ribs and decreased mid to wide thorax diameter ratio in infancy), feeding difficulties and impaired swallowing, dysmorphic features (hairy forehead, full cheeks, protruding philtrum, micrognathia), developmental delay and intellectual disability. Additional features may include kyphoskoliosis, joint contractures, diastasis recti, muscular hypotonia. There is increased risk of hepatoblastoma.
Kallmann syndrome-heart disease syndrome (ORPHA:2326)
Kallmann syndrome with cardiopathy is characterised by hypogonadotropic hypogonadism associated with gonadotropin-releasing hormone (GnRH) deficiency, anosmia or hyposmia (with hypoplasia or aplasia of the olfactory bulbs) and complex congenital cardiac malformations (double-outlet right ventricle, dilated cardiomyopathy, right aortic arch). It represents a distinct clinical entity from Kallmann syndrome.
Epidemiology
Less than 10 cases have been described so far.
Etiology
The aetiology is unknown but both autosomal recessive and dominant modes of inheritance, de novo mutations and a teratogenic origin have been suggested.

                            Last update: 
                            September 2007
Kandori fleck retina (ORPHA:99179)
Kandori fleck retina is a rare, genetic retinal dystrophy disorder characterized by irregular, sharply defined, yellowish-white lesions of variable size that are distributed mainly in the nasal equatorial region of the retina, with a tendency to confluence, that are not associated with any vascular or optic nerve abnormalities. They frequently manifest as mild and stationary night blindness.