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Variable expressivity of Malan syndrome.

Atanu Kumar Dutta¹

¹Biochemistry, All India Institute of Medical Sciences, Kalyani, Kalyani, West Bengal, India atanu.biochem@aiimskalyani.edu.in.

BMJ Case Reports

|October 17, 2024

Summary

This study identifies a novel NFIX gene variant in a family with developmental delay and distinct facial features. The findings highlight variable expressivity in Malan syndrome, impacting neurodevelopment differently across affected individuals.

Keywords:

Genetics Pediatrics

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Area of Science:

Genetics
Neurodevelopmental Disorders
Clinical Medicine

Background:

Malan syndrome is a rare genetic disorder characterized by developmental delay, intellectual disability, and distinctive facial features.
The NFIX gene plays a crucial role in brain development, and mutations in NFIX have been linked to various neurodevelopmental conditions.

Observation:

A family presented with a child exhibiting developmental delay, macrocephaly, dysmorphic facial features, and autism.
The child's mother shared macrocephaly and similar facial features but lacked the neurodevelopmental issues observed in her son.

Findings:

Genetic analysis revealed a heterozygous frameshift variant (NFIX: c.34_41dupGGGATACC) in both the child and his mother.
The clinical presentation in the child and mother was consistent with Malan syndrome, despite differing neurobehavioral phenotypes.

Implications:

This case underscores the significant variable expressivity of Malan syndrome, even within the same family.
Understanding NFIX variant expressivity is crucial for accurate genetic diagnosis and counseling in families with developmental disorders.
Further research into genotype-phenotype correlations in Malan syndrome is warranted to elucidate the mechanisms underlying variable expressivity.