Neonatal Inflammatory Skin and Bowel Disease 1 (<scp>NISBD1</scp>): A Case of <scp><i>ADAM17</i></scp> Homozygous Mutation

Neonatal inflammatory skin and bowel disease 1 (NISBD1) is a rare autosomal recessive disorder caused by mutations in ADAM17, characterized by chronic diarrhea, failure to thrive, rash, and recurrent bacterial infections. Cutaneous manifestations include the presence of a collodion membrane at birth, diffuse scaly erythematous patches and thin plaques, evanescent pustules, and/or erythroderma. We present a case of a 6-week-old full-term male with a diffuse red, focally eroded, pustular eruption in association with chronic diarrhea and failure to thrive. Genetic testing identified a novel, homozygous pathogenic ADAM17 variant, p.(Glu150=) (GAG > GAA): c.450G > A, disrupting the splice donor site and confirming the diagnosis of NISBD1.