Phenotype Expansion of Malan Syndrome: New Cases and a Review of the Literature

Malan syndrome is an ultra-rare overgrowth syndrome caused by pathogenic variants or deletions in nuclear factor one X (NFIX) located at 19p13.2. Here, we report a comprehensive literature review and phenotyping of known patients with Malan syndrome and present a novel cohort of eight patients. This report further establishes the common characteristics of Malan syndrome, expands the ophthalmologic features and airway distress phenotypes, and provides updated management recommendations.