A Rare Co-occurrence of Duchenne Muscular Dystrophy and Glycerol Kinase Deficiency Associated With Xp21 Contiguous Gene Deletion Syndrome: A Case Report

Glycerol kinase deficiency is an X-linked disorder and can occur in isolation or combined as part of the Xp21 continuous gene deletion syndrome. We report the first offspring of a non-consanguineous couple with this contiguous gene deletion syndrome. There was a family history of short stature and learning difficulties, and a personal history of two hospitalizations due to prostration, hypoglycemia, and metabolic acidosis, the first of which occurred at six months of age. The patient was referred to a neurodevelopment consultation due to a global developmental delay detected at two years of age and a genetic consultation at four years old. The array comparative genomic hybridization study identified a maternally inherited hemizygous deletion of the Xp21 region of approximately 6.08 Mb that included both Duchenne muscular dystrophy and glycerol kinase genes, confirming the diagnosis. The patient was referred to metabolic and neurology consultations. Motor examination revealed a waddling gait when running, calf hypertrophy, and a positive Gower's sign. Laboratory evaluation was notable for elevated creatine kinase, hyperglyceroluria, pseudohypertriglyceridemia, and increased transaminases. The patient had a normal adrenocorticotropic hormone stimulation test and normal aldosterone and renin levels. Currently, he has a multidisciplinary team follow-up, including therapies. He maintains deflazacort therapy and follows a nutrition plan based on a fat-restricted diet and avoidance of prolonged fasting to prevent further metabolic crises. This case highlights the importance of identifying the exact genetic defects, in addition to a global picture of symptoms. In our case, it was possible to diagnose complex kinase deficiency along with Duchenne muscular dystrophy. Consequently, it was optimal for multi-profile medical care accompanied by an adequate nutritional plan.