W*****B
发帖数: 4796 | 1 全世界只有20几个人
An 11-Year-Old Got Most Of Her Genes From Her Dad, And Almost None From Her
Mom
BuzzFeed News Reporter
An 11-year-old girl from the Czech Republic was born with genes that came
almost entirely from her father, instead of half from each parent.
Only about 25 people in the world — all girls — have been reported with
this genetic syndrome, and the Czech girl appears to be the first to have
inherited it without developing cancer.
“Ten to fifteen years ago, we didn’t think this condition was compatible
for life,” clinical geneticist Jennifer Kalish of the Children’s Hospital
of Philadelphia, who was not involved in the new case, told BuzzFeed News.
Kalish heads a lab investigating ways to help children with imprinted gene
disorders, conditions in which at least one gene is doubled up from mom or
dad. “It doesn’t happen every day,” she said. Russell-Silver syndrome,
for example, leads to stunted growth when a child inherits two copies of
chromosome 7 from their mother. Although rare, more of these cases are
turning up due to improved genetic testing worldwide.
Researchers found the Czech case because the girl’s parents were trying to
understand why she was deaf, as reported in April in the Journal of Human
Genetics.
When she was 9 years old, a genetic test revealed that she had two identical
copies of a rare gene. At first, the scientists thought it was extremely
bad luck, inheriting the same super-rare gene twice, once from each parent.
But as it turned out, the rare gene was, “surprisingly, not in her mother,
” wrote the scientific team, led by Irena Borgulová of the Centre for
Medical Genetics and Reproductive Medicine Gennet in Prague. Which meant she
had inherited two copies of her father's gene.
Subsequent testing showed that it wasn’t just that one gene — she had
doubled up on her father’s genes in almost all of her chromosomes in most
of her cells.
The girl is not quite a twin of her father, but what’s known as a genetic
“mosaic,” showing variation in different tissues. Only about 7% of her
blood cells, for example, showed any maternal genes. And 74% of the cells in
her saliva held only paternal genes.
Now 11, the girl does bear a telltale sign of the syndrome: one leg longer
and thicker than the other, according to the study. The bigger leg just got
more of the dad-dad genes.
How did this happen? The classic biology class story of a sperm fertilizing
an egg in a musical crescendo that has them first unzipping their genes and
then swapping them together to create a “zygote” is a much messier process
in reality. In the girl’s case, instead of the DNA from her father’s
sperm and mother’s egg pairing up this way, two copies of the father’s
genes zipped together to create a dad-dad set of 23 chromosomes, the full
human genome.
For this to happen in small stretches of genes is rare, about 1 in 10,000
births. It’s rarer still for it to happen across the entire genome, as it
did in this girl’s case. When the zygote split to create more cells, most
ended up with the dad-dad genome.
For the 25 other cases, this doubling resulted in cancer, perhaps because
their paternal DNA included double helpings of cancer-prone genes. So far
the 11-year-old has avoided that fate.
Her deafness, though, may have been caused by her plethora of dad-dad genes,
though not the gene that the doctors had initially suspected: Double copies
of that gene are found in about 1 in 50 Europeans, with no discernible
health effects.
“The cause of the deafness remains unknown,” the study found. | T*********s
发帖数: 20444 | | x********e
发帖数: 35261 | 3 不一样，这小姑娘基本上就是个纯合体，她父亲是杂合体。所以她父亲带的那份突变位
点传到她身上就成了隐性突变。
这小姑娘能活说明她爹的基因相当好了
【在 T*********s 的大作中提到】
: 如果日了，就是自己日自己？
| W*****B
发帖数: 4796 | 4 Identical的双胞胎兄弟相互日，那才是自己日自己。
【在 T*********s 的大作中提到】
: 如果日了，就是自己日自己？
| s**********a
发帖数: 1853 | 5 这种ri了没有用，跟日自己左手没差别，没有受精啊。
楼贴的老爸要日他女儿的话，会有受精反应啊
【在 W*****B 的大作中提到】
: Identical的双胞胎兄弟相互日，那才是自己日自己。
| w*********a
发帖数: 9279 | 6 太恶了。
【在 s**********a 的大作中提到】
: 这种ri了没有用，跟日自己左手没差别，没有受精啊。
: 楼贴的老爸要日他女儿的话，会有受精反应啊
| T*********s
发帖数: 20444 | 7 主要是我想起了predestination
自己把自己介绍给自己，自己日了自己生出了自己
【在 W*****B 的大作中提到】
: Identical的双胞胎兄弟相互日，那才是自己日自己。
| M*****8
发帖数: 17722 | 8
Her
我曾经有几次收获BellPeppers，
里面一个种子都没有，肉正常。
遗传学的有些理论也许并不对。
【在 W*****B 的大作中提到】
: 全世界只有20几个人
: An 11-Year-Old Got Most Of Her Genes From Her Dad, And Almost None From Her
: Mom
: BuzzFeed News Reporter
: An 11-year-old girl from the Czech Republic was born with genes that came
: almost entirely from her father, instead of half from each parent.
: Only about 25 people in the world — all girls — have been reported with
: this genetic syndrome, and the Czech girl appears to be the first to have
: inherited it without developing cancer.
: “Ten to fifteen years ago, we didn’t think this condition was compatible
| M*****8
发帖数: 17722 | 9
我觉得植物长果子，可以无须经过受精就能开始。
因此也无须有仔，只需要某些特殊未知物质的刺激。
这特殊未知的物质，一般在受精后才出现，仅此而已。
生物学千老，如果能搞明白这个机制，应该可获炸药奖。
实际意义也非常大，非常有商业价值，应能提高农业生产。
【在 M*****8 的大作中提到】
:
: Her
: 我曾经有几次收获BellPeppers，
: 里面一个种子都没有，肉正常。
: 遗传学的有些理论也许并不对。
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