Jewish Genetic Disorders (JGDs) For Healthcare Professionals

Welcome to the Jnetics Healthcare Professional portal. Here you will find information on genetic disorders that are relatively more common in the Ashkenazi Jewish community than in the general population. These disorders, though rare, are up to 10 times more prevalent amongst people of Ashkenazi ancestry.

The time-to-diagnosis for Jewish genetic disorders can be unnecessarily and distressingly long for patients and their families. If you encounter a patient with unexplained symptoms and possible Ashkenazi Jewish heritage, please consider the possibility that these two factors may be connected. Highlighting this in your referral letter may help speed up their diagnosis.

Below is a symptom checker to help identify possible Jewish genetic disorders along with their carrier frequencies in the Ashkenazi population. Disorders covered include:

  • very rare and severe life-limiting recessive conditions;
  • relatively more common recessive disorders exhibiting variable symptoms that are often misdiagnosed or mistaken for other conditions; and
  • dominant disorders with variable penetrance that range significantly in their severity and age of onset.

For more detailed information on screening options available and specific Jewish genetic disorders including existing support and onward referral pathways, please click on the relevant heading on the right hand sidebar. Information for patients including how to talk to your GP can be found here on the main Jnetics website and does not require access to the healthcare professional portal.

All the information on the Jnetics website has been verified by medical experts.

Clinical features may include:

Apparently normal development before 3 to 6 months
Progressive weakness, loss of motor skills, decreased attentiveness and increased startle response
Progressive evidence of neurodegeneration including seizures, blindness, spasticity
Eventual total incapacitation
Fundoscopy typically shows a grey-white area around the retinal fovea centralis, due to lipid-laden ganglion cells, leaving a central ‘cherry-red’ spot

Classic infantile TSD is a severe recessive condition characterised by progressive deterioration of the nervous system beginning at approximately 3-6 months of age and usually resulting in death by the age of 4-5 years.

1 in 27

Clinical features may include:

Premature development of pubic hair
Hirsutism
Acne
Alopecia
Anovulation
Menstrual dysfunction
Decreased fertility
Tall stature, accelerated linear growth velocity, and advanced skeletal maturity

Congenital adrenal hyperplasia results from a defect in the biosynthetic pathway of cortisol and/or aldosterone. NCAH is a recessive condition characterised by milder enzyme dysfunction and manifests most commonly in adolescence or early adulthood as a common cause of hyperandrogenism. It may be clinically indistinguishable from PCOS.

1 in 3

Clinical features may include:

Abdominal swelling – due to enlarged liver and/or spleen
Difficulty in feeding and/or swallowing
Progressive loss and/or delay of early motor skills
Progressive low muscle tone
A ‘cherry red spot’ on the macula (as seen in Tay-Sachs disease)
Prolonged jaundice and progressive liver failure

Severe recessive neurodegenerative enzyme deficiency in which sphingomyelin accumulates in various organs, causing rapid deterioration and death in infancy. Symptoms appear by about six months including loss of brain function and enlargement of the liver and spleen.

1 in 90

Clinical features may include:

Pronounced developmental delay in gross and fine motor skills
Marked cognitive development delay
Visual problems including: corneal clouding, retinal degeneration, pseudo-strabismus, sensitivity to light
Hypotonia

Neurodegenerative recessive condition characterised by significant psychomotor and cognitive development delay, visual impairment, and poor muscle tone.

1 in 100

Clinical features may include:

Convulsions caused by hypoglycaemia and lactic acidosis in neonates
Hepatomegaly, lactic acidosis, failure to thrive, hyperuricaemia, hyperlipidaemia, hypertriglyceridaemia and / or hypoglycaemic seizures
Irritability, pallor, cyanosis, hypotonia, tremors, loss of consciousness and apnoea
Characteristic rounded ‘doll’s face’ due to deposition of fat
Enlarged liver sometimes accompanied by marked abdominal distension
Retarded growth
Eruptive xanthomas or gouty tophi on the extensor surfaces of the extremities
Uric acid arthropathy
Bleeding, epistaxis, iron-deficiency anaemia

Recessive condition characterised by growth retardation and accumulation of glycogen and fat in the liver and kidneys resulting in hepatomegaly and renomegaly.

1 in 70

Clinical features may include:

Hepatosplenomegaly
Anaemia and thrombocytopaenia
Bone manifestations including osteopenia, lytic lesions, pathological fractures, chronic bone pain, bone infarcts, osteonecrosis and skeletal deformities
Lung involvement includes interstitial lung disease and occasionally pulmonary hypertension
Spinal cord or nerve root compression may occur secondary to bone disease or coagulopathy

Recessive disease resulting from a deficiency of the lysosomal enzyme acid beta glucosidase. This deficiency leads to the accumulation of glycolipids in macrophages, particularly those in the bone marrow, liver, spleen and lungs.

1 in 12

Clinical features may include:

Hyperpigmentation with café-au-lait spots
Low birth weight or small for age, short stature in later childhood
Triangular shaped facies
Skeletal abnormalities including radial ray defects such as hypoplasia of the thumbs and radial hypoplasia
Microcephaly, microphthalmia and conductive deafness
Cardiac malformations such as PDA, VSD, PS, AS and coarctation
Renal abnormalities include unilateral renal aplasia, renal hypoplasia, horseshoe kidneys or double ureters
Atrophic or dysmorphic gonads with associated genitourinary abnormalities and resultant reduced fertility

Recessive disorder characterised by congenital abnormalities,  defective haemopoiesis and a high risk of developing AML and certain solid tumours. A clinically heterogeneous condition: patients can have a wide variety of abnormalities.

1 in 89

Clinical features may include:

Abdominal pain – may be severe but transient
Fever may be the only symptom
Episodes typically last for 48-72 hrs (peak 12 hrs)
Symptoms can recur after days/months/years
Pleuritic chest pain – sudden onset, one-sided, rapidly resolving
Pericarditis
Joint pain resembling gout in acute onset and intensity. Joints normal between attacks
Erysipelas-like rash (10-20%) below the knees
Pelvic pain in women; scrotal pain in men
Myalgia
Vasculitis – HSP, polyarteritis nodosa and Bechets disease are more common in individuals with FMF

Recessive disorder characterised by recurring episodes of painful inflammation in the abdomen, chest, or joints. The standard treatment with cochicine or TNF alpha blocking drugs can shorten bouts of illness and help to prevent complications including amyloidosis which otherwise can result in renal failure.

up to 1 in 6

Clinical features may include:

Feeding difficulties
Hypotonia
Diminished tears
Decreased or absent deep tendon reflexes
Decreased taste and absence of fungiform papillae of tongue
Poor balance
Autonomic crises
Optic nerve atrophy

Recessive neurodegenerative disorder affecting the autonomic and sensory nervous systems. Clinical signs and symptoms are present from birth and affect the cardiovascular, gastrointestinal, neurological, renal and other systems.

1 in 30

Clinical features may include:

Epistaxis
Easy bruising
Menorrhagia
Abnormal bleeding during or after surgery, injury, or childbirth
Abnormal bleeding during dental extraction
Bleeding manifestations at circumcision

Recessive bleeding disorder characterised by easy bruising and abnormal bleeding. Most patients have few symptoms: the disorder may manifest as an incidental laboratory finding.

1 in 12

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