Chromosome anomalies in a population referred for cytogenetic analysis. a five years experience in Alexandria, Egypt

الملخص EN

-kground : Chromosome abnormalities are significant cause of human morbidity and mortality.

Numerical a well as structural chromosome aberrations can cause mental, growth and developmental delay, disorders of sexual development, congenital defects, spontaneous miscarriage and infertility.

Aim : the study aimed to identify the frequency and pattern of chromosomal aberrations that play a major role in the causation of different genetic diseases.

Subjects and methods : Chromosome analysis was performed on 2326 Egyptian patients referred to the cytogenetic unit of the Human Genetics Department, Medical Research Institute, University of Alexandria, Egypt, over a period of 5 years.

Different cytogenetic techniques were used including Giemsa Trypsin banding technique, high resolution banding technique and induction of breakage.

Results :Chromosome abnormalities were detected in 513 (22.

1 %) of the referred cases.

Autosomal aberrations were present in 435 (84.

8 %) of cases with chromosome abnormalities, while sex chromosome abnormalities were detected in 78 (15.

2 %) of cases.

The most common autosomal abnormality was trisomy 21 representing 73.

7 % (378 cases) of all chromosome abnormalities.

Turner syndrome was the most common sex chromosome anomaly and represented 11.

1 % (57 cases) of total chromosome anomalies.

Translocation was the most common structural chromosome aberrations of autosome detected in 6.

6 % (34 cases) of all chromosome abnormalities, followed in order of frequency by breaks, deletions, marker chromosome, inversions, insertions, and complex rearrangement.

Conclusion :The results confirm the significant contribution of chromosomal abnormalities in the genesis of genetic diseases.

This high frequency of chromosomal aberrations emphasizes the importance of thorough cytogenetic examination