Cri du Chat Sendromu Tanısıyla İzlenen Olguların Klinik ve Moleküler Özellikleri ile Genotip-Fenotip Korelasyonu Açısından Değerlendirilmesi

Abstract

Cri du chat syndrome (CdCS) is a rare chromosomal disorder caused by deletions of varying sizes on the short arm of chromosome 5. The most characteristic features of the syndrome include a high-pitched cat-like cry, developmental delay, intellectual disability, and distinctive facial dysmorphism. The severity of clinical manifestations may vary depending on the size and location of the deletion. Chromosomal microarray analysis enables a more detailed evaluation of genotype–phenotype correlations. In this study, the clinical, laboratory, imaging, and genetic characteristics of 23 patients diagnosed with CdCS were comprehensively evaluated. Demographic and clinical data were collected retrospectively and prospectively, and genotype–phenotype correlations were investigated in 15 patients who underwent chromosomal microarray analysis. Female patients accounted for 60.9% of the cohort. The most common clinical findings were language and motor developmental delay and intellectual disability (100%), followed by a high-pitched cry (95%), microcephaly (87%), epicanthal folds (82.6%), hypertelorism (81.8%), micrognathia (81.8%), and feeding difficulties (81%). Chromosomal microarray analysis revealed an interstitial deletion in one patient and terminal deletions in the remaining patients. Furthermore, the 4.7 Mb terminal deletion identified in our cohort represents one of the smallest deletions reported in the literature to be associated with the CdCS phenotype. Increasing deletion size was associated with a younger age at diagnosis, supporting the concept that larger deletions result in a more severe clinical phenotype. In addition, micrognathia and clinodactyly were found to be potentially associated with deletions proximal to the 5p15.3 region. In conclusion, this study represents one of the largest CdCS cohorts reported from Türkiye, providing a comprehensive characterization of the clinical and molecular features of the syndrome, identifying one of the smallest terminal deletions reported in the literature, and contributing important data regarding genotype–phenotype correlations. Larger multicenter studies are needed to validate these findings and to further define the critical genomic regions involved in CdCS.