Genotype-phenotype correlations and expansion of the molecular spectrum of AP4M1-related hereditary spastic paraplegia
نویسندگان
چکیده
BACKGROUND Autosomal recessive hereditary spastic paraplegia (HSP) due to AP4M1 mutations is a very rare neurodevelopmental disorder reported for only a few patients. METHODS We investigated a Greek HSP family using whole exome sequencing (WES). RESULTS A novel AP4M1A frameshift insertion, and a very rare missense variant were identified in all three affected siblings in the compound heterozygous state (p.V174fs and p.C319R); the unaffected parents were carriers of only one variant. Patients were affected with a combination of: (a) febrile seizures with onset in the first year of life (followed by epileptic non-febrile seizures); (b) distinctive facial appearance (e.g., coarse features, bulbous nose and hypomimia); (c) developmental delay and intellectual disability; (d) early-onset spastic weakness of the lower limbs; and (e) cerebellar hypoplasia/atrophy on brain MRI. CONCLUSIONS We review genotype-phenotype correlations and discuss clinical overlaps between different AP4-related diseases. The AP4M1 belongs to a complex that mediates vesicle trafficking of glutamate receptors, being likely involved in brain development and neurotransmission.
منابع مشابه
AP4 deficiency
Objective To describe the clinico-radiological phenotype of 3 patients harboring a homozygous novel AP4M1 pathogenic mutation. Methods The 3 patients from an inbred family who exhibited early-onset developmental delay, tetraparesis, juvenile motor function deterioration, and intellectual deficiency were investigated by magnetic brain imaging using T1-weighted, T2-weighted, T2*-weighted, fluid...
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