Variable expressivity of Malan syndrome.

We describe the family of a patient with developmental delay, macrocephaly, dysmorphic facial features and autism. His mother also shared similar facial features and macrocephaly but not his neurobehavioural issues. Subsequently, both the child and his mother were found to have a heterozygous frameshift variant NFIX: c.34_41dupGGGATACC. The child and his mother had many features consistent with a genetic diagnosis of Malan syndrome. Therefore, this family highlighted the variable expressivity of Malan syndrome.