# 22q11.2 Deletion Syndrome: Influence of Parental Origin on Clinical Heterogeneity

## TL;DR

This study investigates how the parental origin of a genetic deletion affects the clinical features in 22q11.2 deletion syndrome.

## Contribution

The study identifies specific clinical features associated with the maternal origin of the 22q11.2 deletion.

## Key findings

- Truncus arteriosus, pulmonary atresia, seizures, and scoliosis were only found in patients with maternal deletion origin.
- Congenital heart disease, endocrinological alterations, and genitourinary abnormalities were more common in maternal deletion origin.
- Parental origin does not significantly affect most clinical signs but may influence severity in some cases.

## Abstract

22q11.2 deletion syndrome (22q11.2DS) shows significant clinical heterogeneity. This study aimed to explore the association between clinical heterogeneity in 22q11.2DS and the parental origin of the deletion. The parental origin of the deletion was determined for 61 individuals with 22q11.2DS by genotyping DNA microsatellite markers and single-nucleotide polymorphisms (SNPs). Among the 61 individuals, 29 (47.5%) had a maternal origin of the deletion, and 32 (52.5%) a paternal origin. Comparison of the frequency of the main clinical features between individuals with deletions of maternal or paternal origin showed no statistically significant difference. However, Truncus arteriosus, pulmonary atresia, seizures, and scoliosis were only found in patients with deletions of maternal origin. Also, a slight difference in the frequency of other clinical features between groups of maternal or paternal origin was noted, including congenital heart disease, endocrinological alterations, and genitourinary abnormalities, all of them more common in patients with deletions of maternal origin. Although parental origin of the deletion does not seem to contribute to the phenotypic variability of most clinical signs observed in 22q11.2DS, these findings suggest that patients with deletions of maternal origin could have a more severe phenotype. Further studies with larger samples focusing on these specific features could corroborate these findings.