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ABSTRACT. Dystrophic epidermolysis bullosa (DEB) is an inherited skin fragility disorder that presents various clinical manifestations. DEB is characterized by separation of sublamina densa tissue and abnormalities in the anchoring fibrils that result from mutations in COL7A1 and subsequent defects in type VII collagen. A 16-month-old boy was diagnosed with Hallopeau-Siemens recessive DEB on the basis of typical skin lesions composed of multiple blisters with moderately healed erosions, scarring on trauma-exposed body sites, including hands and feet, pseudosyndactyly and flexion contractures of the toes, and severely dystrophic nails on the right hand. Genomic DNA from the patient and parents were subjected to direct sequencing for the COL7A1 gene. Two heterozygous mutations were detected in the affected child; one novel mutation designated c.4232delC in exon 38 and a single-base COL7A1 mutation in Korean RDEB substitution (c.6573+1G>C) in intron 81. Deletion of a single cytosine at codon 1411 within exon 38 had produced a frameshift mutation that created a stop codon at codon 1427 (p.Pro1411Leufs*17). This intronic base substitution had led to aberrant splicing and a premature termination codon. This is a novel mutation of COL7A1 associated with DEB in a Korean patient, adding to the range of COL7A1 mutations related to DEB.

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Charcot–Marie–Tooth disease type 4C (CMT4C) is an autosomal recessive neuropathy associated with SH3TC2 mutations, resulting in slow conduction velocity via hypomyelination. The occurrence of CMT4C in demyelinating Charcot–Marie–Tooth (CMT) varies among ethnicities, and several variants have been reported as the founder mutation. In Korea, the incidence of CMT4C was calculated as approximately 2%, and all patients have compound heterozygous mutations, which is partly due to the prohibition of consanguineous marriage. Herein, we describe a 25-year-old male who presented a slowly progressive limb weakness and impaired vibration sensation. Whole-exome sequencing revealed homozygous variants c.929G>A of SH3TC2 after identifying negative multiplex ligation-dependent probe amplification results of PMP22. Based on our literature review, this is the first CMT4C patient with a homozygous variant with each allele inherited from both the parents.