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)