Excessive homozygosity identified by chromosomal microarray at a known GCDH mutation locus correlates with brain MRI abnormalities in an infant with glutaric aciduria.

Herein, we report a conceptually novel clinical case highlighting the diagnostic implications of excessive homozygosity and its correlation with brain MRI abnormalities in an infant with GA1. The case also points a need for an extra amount of caution to be exercised when evaluating patients with "negative exomes."