The discovery of dozens of new abnormal chromosomes could help further genetic and cloning research, according to experts from a research institute in Guangzhou, South China's Guangdong Province.

 

Scientists from the Technological Center for Healthy Birth under the Guangdong Family Planning Research Institute have discovered 39 cases involving abnormal chromosomal karyotypes, which are believed to be the first cases on record in the world.

 

Director of the center Zheng Lixin told China Daily yesterday that the cases have been verified by the National Laboratory of Medical Genetics in Hunan Province.

 

The new discoveries follow the analyses of 5,000 blood samples since 1996, bringing the number of abnormal chromosomal karyotypes to be reported first by Chinese scientists to 1,838, Zheng said.

 

In one of the cases, chromosomal abnormalities caused retinoblastoma, a tumor in the retina, in a four-year-old girl to develop into cancer.

 

In another case involving a 22-year-old woman who was born without a uterus, tests showed that an abnormal chromosomal karyotype led to the loss of a gene necessary for uterine formation.

 

The scientists also discovered that an abnormal chromosomal karyotype was the reason for the low sperm count of a pair of twin brothers.

 

Certain hereditary conditions and low reproductive capacity resulting from the presence of abnormal chromosomal karyotypes cannot be cured effectively at present, Zheng said.

 

Zheng said the new discoveries would help to boost the efforts of scientists in the fields of genetics and cloning.

 

Abnormal chromosomal karyotypes can be attributed to exposure to chemicals, radioactivity or viruses. Their discovery can also help in the assessment of environmental pollution, he said.

 

(China Daily February 17, 2006)