A Novel PSAP Gene Mutation in A Lebanese Patient with A Limited Phenotypic Expression

Metachromatic leukodystrophy is an autosomal recessive neurodegenerative disorder that affects the central and peripheral nervous system and falls under the family of lysosomal storage diseases (LSDs). It is divided into three clinical forms (late infantile, juvenile, and adult) depending on how early the disease manifests and with varying prognosis for each form. Common presentations of the disease include cognitive, behavioral, and motor symptoms. Here, we present a Lebanese patient with a novel variant in the prosaposin gene, confirming the diagnosis of metachromatic leukodystrophy due to saposin B mutation, with a phenotypic expression of the disease limited to an attention deficit disorder, and a clear leukodystrophy.