September 15, 2016
A 22-year-old woman with slowly progressive cerebellar ataxia since the age of 5, hypodontia, and hypogonadothrophic hypogonadism
4H Leukodystrophy
- Background:
- 4H syndrome is a genetic disorder that displays an autosomal recessive inheritance pattern. It is characterized by hypomyelination, hypogonadotropic hypogonadism, and hypodontia.
- The causative genes that can be traced are the mutated POLR3A and POLR3B genes.
- Clinical Presentation:
- Patients with 4H leukodystrophy have delayed puberty, low baseline LH and FSH levels, and no response to pituitary stimulation with GnRH. Progressive cerebellar dysfunction and cognitive impairment are also present.
- The age of onset is variable.
- Most patients exhibit dental abnormalities, with several teeth failing to develop.
- Key Diagnostic Features:
- The presence of central nervous system hypomyelination and hypogonadotropic hypogonadism is very suggestive of the disease.
- Preserved myelination of the optic radiations, atrophy of the cerebellum, and thinning of the corpus callosum are typical MRI findings.
- Differential Diagnoses:
- Hypomyelination and congenital cataract (HCC)
- Cockayne syndrome
- PCWH syndrome (peripheral demyelinating neuropathy central dysmyelinating leukodystrophy)
- Pelizaeus–Merzbacher disease
- Vanishing white matter
- Treatment:
- There is no specific treatment for this condition.
