A Typical Neuroaxonal Dystrophy or an Atypical Form of Huntington Disease?

Infantile neuroaxonal dystrophy (INAD) is a rare degenerative disorder of the nervous system with autosomal recessive inheritance, classified within the group of neurodegeneration with brain iron accumulation. Symptoms typically begin between six months and three years of age, presenting with psychomotor regression, hypotonia, and progressive spastic tetraparesis.

We describe a case of INAD with an unusual clinical presentation. The patient carried a prior genetic diagnosis of Huntington disease, but the clinical features were inconsistent with Huntington disease.

The discordance between genetic findings and clinical presentation prompted further investigation, leading to the diagnosis of INAD. This case illustrates the diagnostic challenge posed by overlapping clinical features in neurodegenerative diseases.

This case underscores the importance of considering alternative neurodegenerative disorders in the differential diagnosis of rare diseases. It highlights the critical role of correlating genotype and phenotype to ensure diagnostic accuracy and appropriate patient management.