2q13

2q13 refers to a cytogenetic location on the long arm (q) of chromosome 2, specifically the band designated q13. The exact base-pair coordinates vary with the reference genome assembly, but the region is assessed in chromosomal microarray testing to identify copy number variations.

Two main conditions are associated with this region: 2q13 microdeletion syndrome and 2q13 microduplication syndrome. The 2q13 microdeletion syndrome is characterized by developmental delay or intellectual disability, speech and language difficulties, motor delays, and often dysmorphic facial features. Congenital anomalies, including heart defects, have been reported in some individuals, though the presentation is variable. The 2q13 microduplication syndrome presents with a broader range of phenotypes, from typically developing individuals to those with developmental delay, autism spectrum disorders, and mild dysmorphism; congenital anomalies can occur but are not universally present.

Genotype-phenotype correlations for CNVs in the 2q13 region are not yet fully established. The deleted or duplicated interval usually contains multiple genes, and changes in gene dosage are thought to contribute to the observed features, with considerable variability in expressivity and penetrance. Most cases arise de novo, but inherited cases have been described when a parent carries the same CNV, affecting recurrence risk estimates.

Diagnosis is typically made by chromosomal microarray analysis (array CGH or SNP array). In some instances, targeted testing or fluorescence in situ hybridization (FISH) may be used. Management is multidisciplinary and tailored to the individual, emphasizing developmental therapies, monitoring for associated medical issues, and genetic counseling for families. The understanding of 2q13 CNVs continues to evolve through ongoing research.