Severe neonatal presentation of Xp21 contiguous gene deletion: adrenal crisis and neuromuscular involvement.

Background: Xp21 contiguous gene deletion syndrome is a rare X-linked disorder involving deletions of DMD, GK, and NR0B1 (DAX1), leading to a combination of Duchenne muscular dystrophy, glycerol kinase deficiency, and congenital adrenal hypoplasia. Diagnosis can be delayed due to overlapping symptoms, especially in critically ill infants. Case Reports: We describe two male infants presenting in early life with adrenal insufficiency, electrolyte imbalance, hyperpigmentation, and hypotonia. Biochemical findings included elevated ACTH, low cortisol, high CK, and pseudo-hypertriglyceridemia. In the first case, delayed diagnosis led to sudden death at 7 months. In the second case, early clinical suspicion enabled timely genetic testing and family screening. MLPA revealed DMD gene deletion in both cases. In the second case, molecular karyotyping confirmed deletion at Xp21.3-p21.1; the mother and sister were also carriers. Conclusion: Clinicians should consider Xp21 syndromes in male infants with adrenal insufficiency and neuromuscular or metabolic signs. Early recognition and genetic testing are crucial for accurate diagnosis, effective management, and informed family counseling.