oldest evidence of a human hereditary genetic disorder found

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Oldest evidence of a human hereditary genetic disorder found

News-Medical.Net 28-Jun-2004

The discovery of what is believed to be the oldest evidence yet found of

a human hereditary genetic disorder has been announced by researchers at

the Hebrew University of Jerusalem.

The researchers are Dr. Uri Zilberman and , the

Wilbush Professor of Medical Anthropology, both of the Faculty of Dental

Medicine of the Hebrew University and Dr. Silvana Condemi a senior

researcher at the French Research Institute in Jerusalem. They are among

the authors of an article in the June issue of the Journal of Human

Evolution that details the finding of a disease known as amelogenesis

imperfecta in the teeth of a fossil found in archaeological excavations

in Ethiopia. The fossil is dated as 1.5 million years old and is from a

two-year-old Homo erectus child. Homo erectus was a precursor of modern

man.

According to Dr.Zilberman, this is the first recorded evidence from such

an early prehistoric period of a hereditary disorder in which the

specific genes responsible have been identified. Undoubtedly, he said,

there are other hereditary diseases that have come down to us from

prehistoric ancestors and which are yet to be discovered in fossil

remains.

Amelogenesis imperfecta is a hereditary disorder that manifests itself

in tooth enamel that is abnormal in structure, low in mineral content

and hence subject to rapid wear and chipping. The Hebrew University

researchers confirmed the clear presence of the disease in the fossil

sample through x-ray and scanning electron microscope analyses. The

disease appears relatively rarely today (one in 14,000 people in Israel,

one in 8,000 in the U.S.). It is much more common in one area of Sweden

(one in 700).

http://www.huji.ac.il/