Nagoya University has found a patient with a skin disease inherited as a paternal germline mutation.
Researchers from Nagoya University have found a 2-year-old girl with a whole-body skin disease, epidermolytic ichthyosis (EI), caused by a mosaic skin disease, Epidermolytic Nevus (EN), she inherited from a germline cell mutation on her father’s side.
“We took a skin sample from one of these areas and identified the identical keratin 10 mutation that we detected in his daughter,” researcher Yasushi Suga said. “This confirmed that the same mutation was causative of EN in the father and had been transmitted to the daughter as EI.”
EN is when patches of visibly thickened skin appear in small parts of one’s body- known as birthmarks. This occurs from a mutation in the keratin 10 gene, which causes an overgrowth of cells occurs in a small area of the skin’s top layer.
Birthmarks, however, are not inherited, usually, since the genes of sperms are rarely ever mutated. However, when this does happen, the children produced from that sperm could inherit the skin symptom on their entire body, known as EI.
The symptoms of EI are noticeable from birth, as blistering and redness appears all over the body. Unfortunately, the symptoms become worse with time, as the skin becomes thicker and scaly.
The father of the girl with EI, had EN patches on about 0.5 percent of his skin- on his abdomen, groin and hand. When the girl’s parents wanted to know the possibility of their other children inheriting the same disease, the scientists performed DNA sequencing on the father’s semen, and found that 3.9 percent of them had the mutation. However, this had to be coupled with each of these sperm’s fertilization ability.
Comments From Researchers
“Symptoms of mosaic inherited skin disorders are highly visible so diseases can be identified before the birth of affected children, unlike genetic diseases that don’t affect the skin,” said, Michihiro Kono, the corresponding author. “This enables the risk of disease transmission to be determined, and couples to undergo genetic counselling.”
This just comes to show the importance of genetic counseling in preventing such mutations from occurring. Genetic counseling allows people to perform genetic tests in order to fully understand the risk of having children with inherited genetic disorders.
The law that allows licensing for genetic counselors ensures that “professionals who call themselves genetic counselors are able to properly explain complicated test results that could confuse patients and families making important health decisions.”