Paramyotonia congenita (PMC) is characterized by nondystrophic myotonia aggravated by exercise and cold exposure. SCN4A mutations manifest as various phenotypes of channelopathy, including PMC, myotonia congenita, and periodic paralysis. SCN4A-related channelopathy is characterized by autosomal dominant inheritance. Parental gonadal mosaicism is suspected in cases of recurrent de novo mutation in an autosomal dominantly inherited disease. We report a case of two Korean brothers presenting with PMC due to same de novo SCN4A point mutation, probably due to parental gonadal mosaicism.

Adrenoleukodystrophy (ALD) is the most common peroxisomal disorder caused by mutations in the gene, ABCD1, causing abnormal accumulation of very-long-chain fatty acids in the nervous system and adrenal glands. There are various clinical manifestations of ALD. Here we report a 47-year-old male with adrenomyeloneuropathy with cerebral involvement who exhibited progressive gait disturbance and cognitive impairment. A novel frameshift variant (c.95del [p.Val32Alafs*36]) in exon 1 of ABCD1 was identified. This report provides additional information regarding the various clinical characteristics of ALD.

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an immune-mediated neuropathy with heterogeneous features. Appropriate treatment will produce a favorable outcome, but a poor treatment response and severe disability have also been reported. The roles of the clinical phenotypes and electrophysiological features of CIDP as well as of autoantibodies against nodal and paranodal proteins have been highlighted previously due to their association with the treatment response and long-term prognosis. This review addresses the diverse factors associated with the prognosis of CIDP.

Citations

• Tendon-Sparing Extraocular Muscle Enlargement Associated With Chronic Inflammatory Demyelinating Polyradiculoneuropathy
  Antonios D. Dimopoulos, Anne Barmettler
  Ophthalmic Plastic & Reconstructive Surgery.2024; 40(2): e38.     CrossRef

Axonal Charcot-Marie-Tooth disease (CMT2) has most frequently been associated with mutations in the MFN2 gene. MFN2 encodes mitofusin 2, which is a mitochondrial fusion protein that plays an essential role in mitochondrial function. We report CMT2 in a Korean father and his son that manifested with gait difficulties and progressive atrophy of the lower legs. Molecular analysis revealed a novel heterozygous c.2096T>C (p.Leu699Pro) mutation in the exon 18 of MFN2 in both subjects. We suggest that this novel mutation in MFN2 is probably a pathogenic mutation for CMT2.

Ullrich congenital muscular dystrophy (UCMD) is caused by mutations in one of three genes encoding collagen VI. Although UCMD usually shows an early onset, progressive weakness, contractures and hyperlaxity of the joints, and respiratory failure, it is well known to exhibit a wide spectrum of clinical severities. The severities of the phenotypic subtypes are mainly divided according to the ambulation status. We report a patient with the early-severe phenotype of UCMD who was diagnosed by the detection of novel recessive mutations in COL6A1.