PMC9527530_01
Family pedigree. The Proband's family pedigree demonstrates an autosomal
dominant inheritance pattern in the genetically confirmed and clinically
suspected individuals indicated.
10.1177_23247096221117801-fig1.jpg
PMC9527530_01_10.1177_23247096221117801-fig1.jpg
fig1-23247096221117801
She reported a family history of presumed CMT neuropathy based on foot drop and intrinsic hand weakness in her maternal grandfather, mother, brother, two daughters, and one granddaughter, although genetic testing or EDX studies had not been performed on extended family members (Figure 1).
PMC9527530_02
DNA electropherograms. The clinically likely pathogenic heterozygous
DNM2 mutation (c.1609 G>A) is demonstrated in
the Proband (case 1), her brother (case 2), and their clinically
affected mother. The normal allele is present in their unaffected
father, indicating maternal dominant gene transmission. HET =
Heterozygous.
10.1177_23247096221117801-fig2.jpg
PMC9527530_02_10.1177_23247096221117801-fig2.jpg
fig2-23247096221117801
Genetic testing identified a heterozygous missense point mutation in exon 15 of the DNM2 gene (c.1609 G>A) on chromosome 19, resulting in substitution of glycine 537 to serine (p.Gly537Ser) in the Proband and her brother (see arrow, Figure 2). Their mother possessed the same heterozygous missense DNM2 point mutation which was absent in their father (Figure 2), supporting our inference that DNM2 (c.1609 G>A) is causative of DI-CMTB in this family cohort.