A new patient with congenital myasthenic syndrome type 20 due to compound heterozygous missense SLC5A7 variants suggests trends in genotype-phenotype correlation.

ABSTRACT:

Background

Congenital myasthenic syndromes (CMSs) are characterized by hypotonia, episodic apnea, muscle weakness, ptosis and generalized fatigability. CMS type 20 (CMS20) is a rare disorder caused by variants in SLC5A7. In contrast to most other CMSs, CMS20 is also associated with neurodevelopmental disorders (NDDs). Only 19 patients from 14 families have been reported so far.

Methods

We studied a 12-year-old boy with symptoms manifested at six weeks of age. Later, he also showed speech delay, moderate intellectual disability and autism. Analysis of CMS genes known at the time of clinical diagnosis yielded no results. Trio exome sequencing (ES) was performed.

Results

ES revealed compound heterozygosity for two SLC5A7 variants, p.(Asn431Lys) and p.(Ile291Thr). While t

SUBMITTER: Vlckova M 

PROVIDER: S-EPMC10265034 | biostudies-literature | 2023 Jun

REPOSITORIES: biostudies-literature