CYTOGENETIC STUDY OF CHILDREN WITH DEVELOPMENTAL DELAY AND ASSOCIATED ANOMALIES

Document Type : Original Article

Authors

Abstract

Background: Developmental  delay  (DD)  could  be  syndromic  or  non-syndromic,  and collectively  it  affects    10%  of  all  children.  There  are  numerous  causes  of  DD  that  could  be genetical,  hormonal  and/or  neurological.  The  frequency  of  defected  chromosomal  anomalies  in patients  with  DD  is  variable  and  estimates  between  9%  and  36%.  However,  the  accurate diagnosis  needs  further  tests  based  on  the  information  gather  from  parents  and  the  findings  on physical examination.
Objectives: We  aim  to  evaluate  the  pattern  of  chromosomal  abnormalities  in  children  with  DD,  in  order  to  detect  the  treatable  cases,  and  offering  an  appropriate  genetic counseling.       
Patients & Methods: This is a cohort study comprised 40 children with developmental delay and associated congenital anomalies were referred from the outpatient clinic of the pediatric department, El Sayed Galal Hospital, to the Human Cytogenetics department, National Research Centre (NRC), Cairo, Egypt. During the period from December 2015 till June 2018.
     The patients were subjected to the present study. Peripheral  blood  samples  were collected,  cultured,  harvested,  metaphase  spread  and  then  chromosomes  were  stained  for  Gbanding  using  Trypsin-Giemsa  technique.  Chromosomes were analyzed, metaphase spreads were captured, and karyotyping has been done.
Results: 2 cases  out  of  the  40  affected  children  have  structural  chromosomal rearrangements, and 3  out  of  them  carried numerical chromosomal abberations .
Conclusion: Chromosomal  studies  are  valuable  in  detecting  such  cases  with  DD. Prenatal  genetic  diagnosis  is  of  clinical  importance  to  prevent  and  offer  genetic  counseling.   Additionally,  small  proportion  of  apparently  normal  population  could  carry  some  types  of structural chromosomal anomalies.

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