POMT1 and POMT2 mutations in CMD patients: a multicentric Italian study

Area of Science:

• Genetics
• Neurology
• Molecular Biology

Background:

• Mutations in POMT1 and POMT2 genes are associated with Walker-Warburg syndrome (WWS) and milder phenotypes like intellectual disability.
• Congenital muscular dystrophy (CMD) with alpha-dystroglycan deficiency presents with varying clinical and radiological findings.

Purpose of the Study:

• To determine the frequency of POMT1 and POMT2 gene mutations in Italian CMD patients.
• To characterize the phenotypic spectrum associated with these mutations in the Italian population.

Main Methods:

• Screening of POMT1 and POMT2 genes in 61 Italian patients diagnosed with CMD.
• Clinical and radiological assessment of patients with identified mutations.
• Analysis of mutation types and their correlation with phenotypic severity.

Main Results:

• Mutations in POMT1 were found in 13 patients and in POMT2 in five patients, identifying 20 distinct mutations, including eight novel ones.
• Common findings included normal brain MRI with mental retardation and microcephaly (POMT1) and cerebellar hypoplasia (both POMT1 and POMT2).
• Severe phenotypes were linked to frameshift and stop codon mutations, while a WWS phenotype was observed in one POMT1 case.

Conclusions:

• POMT1 and POMT2 mutations are a significant cause of CMD in the Italian population.
• The phenotypic spectrum associated with POMT1 and POMT2 mutations is broader than previously recognized, encompassing a range of neurological and muscular disorders.
• Further research is needed to fully understand the genotype-phenotype correlations in these conditions.