A 38-year-old male visited our clinic for asymmetric upper extremity weakness. The patient reported that, at the age of nine, he had difficulty performing iron bar gymnastics. Since his third decade, he experienced prominent right shoulder and arm weakness, and he presented with facial asymmetry and weakness. Physical examination showed a transverse smile, positive Beevor's sign, and winged scapula (). In addition, he showed facial and bilateral arm and leg weakness with proximal dominance and asymmetricity (right side more severe than the left) on neurological examination. Serum creatinine kinase levels were mildly elevated at 224 unit/L. His mother and elder sister had similar symptoms (). We performed genetic analysis for FSHD. Southern blotting analysis by the EcoRI/BlnI digestion method using genomic DNA revealed that a fragment size of 37 kb, and the number of D4Z4 repeats was nine. Bisulfite sequencing to determine the haplotype of D4Z4 using digestion with HindIII and hybridized with 4qA probe and target sequencing analysis to screen for mutations in the SMCHD1 gene by a next-generation sequencer (Ion PGMTM) were performed for FSHD2 diagnosis. We found reduced DNA methylation ratio (16.8%), D4Z4 haplotype 4qA (homozygous), and c.1580C>T (p.T527M) SMCHD1 mutation, which was previously reported to be a pathogenic allele.\nInformed consent was obtained from the two patients regarding the reporting and publication of this case report.
Patient 3 was an 18-yr-old man complaining of progressive right upper limb weakness over the prior 3 yr. The initial diagnosis was idiopathic right brachial plexopathy. He was a tennis player in his early teens. There was no family history of neuromuscular disease (). Clinical examination of his parents was normal. Remarkable neurological findings included mild bifacial weakness; mild (MRC grade 4) and minimal weakness of the right and left proximal upper limb muscles, respectively; winged scapulae in the right side; and hypoactive deep tendon reflexes. The serum CK was 750 IU/L. Other routine laboratory tests including thyroid function were normal. Audiogram, electrocardiogram, echocardiogram, and nerve conduction studies were unremarkable. The FVC was 4.2 L (98% of predicted). Needle electromyography revealed chronic myopathic changes.