Inheritance: autosomal recessive
Enzyme defect: galactocerebrosidase
Classification of the infantile form by age at onset:
(1) early infantile: before 6 months of age
(2) late infantile: from 6 to 48 months
Later onset forms:
(1) juvenile (between 3 years of age and adolescent)
(2) adolescent
(3) adult
Clinical findings may include any of the following:
(1) weakness
(2) loss of manual dexterity
(3) abnormal gait or ataxia
(4) hemiparesis
(5) muscle hypertonicity
(6) burning paresthesias or other sign of a peripheral neuropathy
(7) variable loss of vision
(8) variable intellectual deterioration
(9) variable progressive neurologic deterioration
The diagnosis if straightforward if there is a family history but can be challenging when presented with the proband,