Investigation of Submicroscopic Chromosomal Anomalies on Patients with Unexplained Intellectual Disabilities with Molecular Karyotyping Açıklanamayan Entellektüel Yetersizliği Bulunan Hastalarda Moleküler Karyotipleme

Main Article Content

Hanife Saat
Mehmet Ali Ergün
E. Ferda Perçin

Abstract

Backround: Intellectual disabilities, developmental delay and accompanying congenital anomalies are rarely seen on general population, but have a large etiologic spectrum. Chromosomal abnormalities are one of the significant reasons of intellectual disabilities, dysmorphic appearance and various congenital anomalies. Conventional cytogenetic techniques can only detect abnormalities greater than 5 Mb. Array based methods can be useful to detect anomalies smaller than 3 Mb to kilobase levels with a ratio of 12-14%. As a result, small interstitial deletions and duplications could be detected and new genes could be discovered with microarray techniques.


Methods: In this study, 29 patients with idiopathic intellectual disability, developmental delay and/or congenital anomaly, had been investigated for small deletions or duplications with “Array CGH 8x60K ISCA”.


Results: Causative/ probably causative pathology was detected in 6 patients and the diagnostic power of these systems was confirmed, and we obtained a yield of 20.6%. Feingold syndrome 1, Williams syndrome with atypical findings, 14q11.2 deletion syndrome and 1p36 deletion syndrome, 13q14.3-q21.1 duplication spanning PCDH17 gene and a duplication in Xp11.4 chromosomal region containing ATP6AP2 gene were detected. We reported second Feingold syndrome with renal agenesis and first case of 14q11.2 deletion syndrome with episodic vomitting attacks.


Conclusion: Microarray technology is the first-tier diagnostic method in patients with intellectual disability with multiple congenital anomalies. The genotype-phenotype correlation studies provide explaining the etiology and molecular mechanism of intellectual disability and developmental delay.

Article Details

Section
Original Research