Donohue syndrome with a homozygous INSR exon 14 deletion: a case report

Donohue syndrome (DS) is a rare autosomal recessive disorder caused by homozygous or compound heterozygous mutations in insulin receptor (INSR), leading to severe insulin resistance. It is characterized by extreme hyperinsulinemia, fasting hypoglycemia, postprandial hyperglycemia, severe growth restriction, and dysmorphic features, with a high mortality rate in the first year due to metabolic instability and infections. We report the case of a 3-month-old Honduran girl with a homozygous exon 14 deletion in INSR who presented with severe insulin resistance, metabolic dysregulation, and dysmorphic facial features. Despite treatment with octreotide, metformin, and maltodextrin, the patient's condition worsened, leading to septic shock, disseminated intravascular coagulation, and multiple organ failure. This case highlights the challenges in correlating genotype with phenotype in DS and emphasizes the importance of understanding how specific INSR mutations influence the treatment response and clinical outcomes.