Familial manifestation of limb-girdle muscular dystrophy associated with FKTN gene: a case report

Abstract

Abstract Introduction: to report a familial case of Limb-girdle muscular dystrophy, type C, 4 (MDDGC4) associated with a homozygous mutation in FKTN gene, highlighting phenotypic variability, diagnostic delay, and atypical clinical features described in the pediatric literature. Description: two siblings were evaluated due to persistent hypertransaminasemia and markedly elevated creatine kinase (CK). Both underwent detailed clinical assessment, laboratorial and imaging exams, hepatologic investigation, and neuromuscular genetic panel testing for diseases. The older sibling, currently 10 years old, had been investigated since birth for hepatomegaly, direct hyperbilirubinemia, and elevated liver and muscle enzymes. After years of unfruitful hepatological investigation, a diagnosis of muscular dystrophy associated with FKTN gene was established by a genetic panel. The patient presented muscle hypertrophy and sleep-disorder, with significant clinical improvement after the use of continuous positive airway pressure. His 5-year-old brother presented a similar clinical presentation, and the same homozygous genetic pattern was identified. Bothpresented cognition with good academic performance. Discussion: this report highlights the importance of creatine kinase (CK) doseage in children with elevated transaminases to prevent diagnostic delay. In addition, it describes clinical manifestations that are poorly documented in pediatric patients with FKTN gene mutations.