Unlikely Genetic Cousins Discovered
May 19, 2016
The New York Jewish Week — Nearly four years ago, an Ethiopian Israeli couple brought their two children to the office of Prof. Ohad Birk, director of the Genetics Institute at Soroka University Medical Center and the Morris Kahn Lab at the National Institute for Biotechnology in the Negev at BGU.
The children had a severe, unnamed muscle disease causing an array of problems, including low muscle tone, developmental delays and heart defects.
“The parents had decided not to have any more children, realizing they had at least a 25 percent chance of having an affected child,” says Prof. Birk.
Prof. Ohad Birk
The genetic screening tests — amniocentesis and IVF with PGD (pre-implantation genetic diagnosis) — typically used to determine whether an embryo carries the disease-causing gene mutation were of no use, because the disease had never been identified.
Determined to provide this family with some answers, Prof. Birk directed his team to take DNA samples from both parents and their children to try and locate mutated regions in the genome common to both children.
Roughly six months after the lab began researching the cause of the family’s disease, a breakthrough happened.
“We were approached by a Bedouin family whose tribe originated in Egypt hundreds of years ago,” Prof. Birk says. “Two of their kids had already died from what seemed to be a very similar disease. Ph.D. student Michael Volodarsky thought it might be the same disease and possibly caused by mutations in the same genes.”
After cross-referencing DNA from the affected children, the team discovered they all shared a similar mutated gene — CCDC174 — that had “annexed” six extra amino acids to the protein it encodes.
The team hit the history books and discovered that there was once commerce between the region of Egypt and the region of Ethiopia where the two families originated.
“They were related hundreds of years ago,” says Prof. Birk.
Based on their findings, Soroka’s Naomi Fisher Bartnoff Genetic Counseling Unit was able to offer both families prenatal genetic testing.
Three months ago, the Ethiopian couple gave birth to a healthy baby.
“Finally, we have an answer,” says the mother.
Read more on The New York Jewish Week website >>
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