# The diagnostic yield of molecular karyotyping: a retrospective single-center study

## TL;DR

This study shows that chromosomal microarray analysis is effective in diagnosing genetic conditions in patients with intellectual disability, developmental delay, and other related disorders.

## Contribution

The study expands the known diagnostic utility of CMA to include epilepsy and dysmorphic features.

## Key findings

- CMA detected phenotype-associated CNVs in 20.3% of ID/DD patients and 23.9% of MCA patients.
- Chromosomal gains or losses were found in 43% of patients with dysmorphic features.
- CMA showed a 15.9% diagnostic yield in patients with epilepsy.

## Abstract

To determine the diagnostic yield of chromosomal microarray analysis (CMA) in different patient groups: intellectual disability and developmental delay (ID/DD), multiple congenital anomalies (MCA), epilepsy, autism spectrum disorder (ASD), reproductive abnormalities, and dysmorphic features.

We retrospectively reviewed microarray data of 176 patients admitted to the Medical Genetics Outpatient Clinic of Necmettin Erbakan University Medical Faculty Hospital from 2016 to 2022. After the copy number variation (CNV) interpretation, we evaluated the diagnostic strength of CMA in each group.

Phenotype-associated CNVs were detected in 20.3% (22/108) of patients with ID/DD, 23.9% (17/71) of patients with MCA, 15.9% of patients (7/44) with epilepsy, 16.6% (4/24) of patients with ASD, and 11.7% (2/17) of those with reproductive abnormalities. Chromosomal gains or losses were found in 43% (35/80) of patients with dysmorphic findings.

This study confirmed the remarkable diagnostic yield of CMA in ID/DD, MCA, and ASD patients, and expanded its value for cases with epilepsy and dysmorphism.