13q31.1 microdeletion: A prenatal case report with macrocephaly and macroglossia

Area of Science:

• Genetics
• Developmental Biology
• Molecular Biology

Background:

• Ras/mitogen-activated protein kinase (MAPK) signaling pathways are crucial for cell differentiation and proliferation.
• Mutations in MAPK pathway genes cause RASopathies, a group of developmental disorders.
• Macrocephaly is a feature of some RASopathies, but prenatal macroglossia is not typical.

Observation:

• A female fetus presented with macrocephaly and macroglossia.
• Array comparative genomic hybridization (array-CGH) identified a 13q31.1 microdeletion.
• The deletion encompassed three genes: SPRY2, NDFIP2, and RBM26.

Findings:

• NDFIP2 is involved in ubiquitination and Ras/MAPK signaling.
• SPRY2 inhibits Ras/MAPK pathways.
• Phenotype-genotype correlation suggests SPRY2 and NDFIP2 as candidate genes for a RASopathy responsible for the observed fetal features.

Implications:

• This case expands the genetic understanding of RASopathies.
• It underscores the utility of array-CGH in prenatal diagnosis for unexplained macrocephaly and macroglossia.
• Genetic investigations for macroglossia should include screening for microdeletions beyond established genetic causes.