Infantile Dilated Cardiomyopathy Diagnosed as Alstrom Syndrome in Later Childhood: A Report of Two Siblings

Background: Alstrom syndrome is a rare autosomal recessive multisystem disorder due to a mutation in the ALMS1 gene, characterized by various combinations of dilated cardiomyopathy (DCM), cone-rod dystrophy, hearing loss, childhood obesity, Type 2 diabetes, along with other system involvement. We report this rare disorder in two siblings presenting as acute cardiac failure due to DCM in infancy. Clinical Description: Case 1: A three-and-a-half-month-old female infant presented with breathlessness and poor feeding for 2 days. She was afebrile with signs of heart failure. Investigations and echocardiography confirmed DCM. Two years later, Case 2 (sibling of Case 1) presented with similar features at 2 months of age, again diagnosed as DCM. Management and Outcome: Both siblings achieved clinical recovery with supportive management. Echocardiography showed improvement in cardiac function by 1 year and 5 months of age in Case 1 and Case 2, respectively. The siblings were noted to develop nystagmus at 2 (Case 1) and 1 (Case 2) year of age, with high hyperopia. On further follow-up, Case 1 and Case 2 were found to develop obesity by 7 and 5 years of age, respectively, with raised glycosylated hemoglobin, and increased insulin (Type 2 diabetes mellitus). Genetic analysis identified homozygous pathogenic variant deletion of exons 13-16 in the ALMS1 gene, thus diagnosing them both with Alstrom syndrome. Conclusion: A self-remitting, infantile DCM may be an initial presentation of an underlying genetic condition like Alstrom syndrome. Regular follow-up and taking together all the systems that get involved over time, help in suspecting this condition, confirmed by genetic analysis.