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

Am J Med Genet A. 2026 Apr 3. doi: 10.1002/ajmg.a.70147. Online ahead of print.

Abstract

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.

Keywords: Malan syndrome; central visual impairment; eustachian tube; optic nerve atrophy; overgrowth.

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