# Prenatally Diagnosed 7q11.23 Copy Number Variations: A Retrospective Case Series

## TL;DR

This study examines prenatal cases of 7q11.23 copy number variations, showing ultrasound anomalies and high termination rates, with inherited cases having milder outcomes.

## Contribution

The study provides new insights into prenatal manifestations and inheritance patterns of 7q11.23 CNVs, emphasizing the importance of genomic testing for counseling.

## Key findings

- 7q11.23 deletions were associated with 100% ultrasound anomalies, including cardiovascular defects and growth restriction.
- 76.5% of ongoing pregnancies with de novo CNVs resulted in termination of pregnancy.
- Inherited CNVs were linked to milder outcomes compared to de novo variants.

## Abstract

Williams‐Beuren syndrome (WBS; OMIM #194050), caused by 7q11.23 deletions, is well‐characterized postnatally, but prenatal manifestations remain poorly defined. This study aims to delineate the prenatal phenotypes, inheritance patterns, and outcomes of 7q11.23 copy number variations (CNVs).

A retrospective study of 20 prenatal cases with 7q11.23 CNVs diagnosed by SNP array or CNV sequencing (CNV‐seq) was conducted. Clinical data, including ultrasound findings, genetic results, and pregnancy outcomes, were analyzed.

Classic 7q11.23 deletions (1.42 Mb median size) were associated with ultrasound anomalies in 100% of cases (11/11), predominantly cardiovascular defects (36.4%, 4/11) and growth restriction (18.2%, 2/11). While 7q11.23 duplications (1.42–3.03 Mb) were associated with anomalies in 50% of cases (3/6), including cleft palate and ventriculomegaly. Inheritance pattern analysis revealed 50% of deletions (6/12) and 42.9% of duplications (3/7) were inherited, either from phenotypically normal or abnormal parents. Termination of pregnancy (TOP) occurred in 76.5% (13/17) of ongoing pregnancies, primarily for de novo CNVs. Four live births involved inherited CNVs.

7q11.23 CNVs exhibit significant prenatal phenotypic variability and inheritance heterogeneity. Advanced genomic testing and inheritance pattern analysis are critical for accurate diagnosis and counseling.

Prenatal 7q11.23 CNVs exhibit 100% ultrasound anomalies in deletions (cardiovascular defects, growth restriction) and 50% in duplications. Inherited CNVs (50% deletions, 43% duplications) correlate with milder outcomes, while de novo variants drive high TOP rates (76.5%), emphasizing genomic testing and parental studies for precise counseling.