It's a vital issue - in my view it is right we would not want if we could avoid it that children suffer. Plenty of communities including I think some jews on this thread go through genetic tests before marrying and I trhink that is a really good thing. I don't see it as morally repugnant eugenics and disablism.
I see it as similar to taking folic acid tablets when pregnant rather than hoping for a child with spina bifida or leaving it in the hands of invented Gods.
The FLDS group I mention above in the US see the having of children with fumarase deficiency as a massive blessing from God as the parents will give love to the children broadly.vice.com/en_us/article/tiny-tombstones-inside-the-flds-graveyard-for-babies-born-from-incest. I don't agree.
"In the 1930s, two families, the Jessops and the Barlows, settled the area around Hildale, Utah, along the border with Arizona, where they founded the FDLS — and began handing down to their descendants a recessive gene for a severe form of mental retardation called Fumarase Deficiency. The birth defect has become increasingly prevalent within the FLDS community since 1990 when it was first identified by Dr. Theodore Tarby, an Arizona pediatric neurologist, now retired but formerly with the Children's Rehabilitative Services in Phoenix. He saw his first case when an FLDS mother brought her severely retarded son to see him. Tarby asked the mother whether any of her other children had problems, and she mentioned a daughter with cerebral palsy — testing proved that she, too, had Fumarase Deficiency syndrome.
The birth defect — an enzyme deficiency — causes severe mental retardation, epilepsy and disfigurement of features. "The retardation is in the severe range — an IQ around 25," Dr. Tarby says. Afflicted children are missing portions of their brain, often cannot sit or stand, and suffer grand mal seizures and encephalitis. Language skills are nonexistent or minimal. "I remember one little girl has a fascination with coins and the only word she could say was 'money,'" the doctor said. Families whose children are affected often avail themselves of state-funded medical care, consistent with the FLDS philosophy of seeking government aid — despite their suspicion of government — which they call "bleeding the Beast."
Until 1990 Tarby says he knew of only 13 cases of Fumarase Deficiency worldwide. Since, it has taken hold in the FLDS community because of intermarriage. "If you have two parents with the gene," Tarby says, "you are going to have a one-in-four chance of having a child afflicted with it." Depending on the severity of the disorder, children may die in childhood or may survive into early adulthood; if a person who has developed the disorder goes on to have a child, his or her chances of passing it on are one in two. But diagnosing the condition is difficult and requires extremely careful testing, the doctor says. His research, published in 2006, identified 20 cases within the Hildale-Colorado City enclave. "I would expect there are going to be Fumarase Deficiency cases there in Texas," he said."