Objective: Chromosomal microarray is a diagnostic test that could detect copy number variations (CNV) with a higher resolution than G-banding. The aim of this study is to determine the contribution of microarray test to diagnosis in dysmorphic patients.

Material and Method: Microarray test results of 236 dysmorphic patients aged between 1 month and 48 years, who were followed up in the Medical Genetics outpatient clinic between January 2017 and December 2019, with intellectual disability, developmental delay, and/or multiple congenital anomaly and of 74 parents were evaluated retrospectively.

Results: In this study, it consisted of 236 dysmorphic patients, 139 (58.9%) of which were boys and 97 (41.1%) were girls. Thirty patients had a pathogenic variant, 2 patients had a likely pathogenic variant, 53 patients had a variant of unknown clinical significance and 3 patients had a benign variant. Pathogenic or likely pathogenic CNV was detected in 13.6% of 236 dysmorphic patients. By detecting well-defined genetic syndromes in 15 patients, the patients were diagnosed. It was observed that 87.5% of pathogenic and possibly pathogenic CNVs were deletions and 12.5% were duplications. When CNVs are evaluated in terms of localization sites; 72 were localized to the autosomal chromosomes, 8 to the X chromosome, and 8 to the Y chromosome.

Conclusion: The use of microarray-based tests instead of G-banding in dysmorphic patients with intellectual disability, developmental delay, and/or major congenital anomalies could be recommended as the first diagnostic test, as this group of patients can be diagnosed earlier. Thus, genetic counseling may be given to these patients, who are diagnosed in a short time, and supportive/therapeutic approaches may be initiated.