Chromosomal abnormalities in Saudi children of Jeddah City

Abstract EN

It is attempted to estimate the incidence of chromosomal disorders, constitutional karyotype and cytogenetic patterns of chromosomal abnormalities in the Western Saudi region.

Further, associations between socio-demographic, obstetrical, medical and environmental factors were also attempted.

Overall incidence of chromosomal disorders was estimated at 2.8 and 2.4 for Down syndrome per thousand Saudi live births.

Cytogenetic analysis revealed preponderance of numerical (92 %) aberrations than structural (8 %).

Down syndrome was the most frequent form of the chromosomal disorders ; in addition, trisomies of chromosome 13 and 18 and monosomy of X was found in lesser frequencies.

A rare form of chromosomal configuration with translocation of chromosome 7 and 10, extra marker chromosome and pericentric inversion in chromosome 3 were also observed.

Trisomy 21 was recorded to have high frequency (94 %) ; other forms like Robertsonian translocation and mosaicism were also detected in lesser frequency.

A significant association between advanced mother ages was confirmed, other factors have no bearing.

Findings are : The estimated incidence of overall chromosomal disorders is lower, but incidence of Down syndrome is higher compared to national and international frequencies.

Down syndrome is the most frequently encountered disorder and karyotypic techniques effectively help diagnosing in most of the cases.