Hutterite gene: SD researchers study lethal syndrome affecting infants
Three Hutterite women gather around a table at Oak Lane Colony in rural Alexandria, relishing the air conditioning. It's mid-afternoon, and they've just come in from working in their gardens since 6 a.m.
They talk about colony life, marriage and children, teasing each other as they tell stories. All three have young children.
None of the children suffer from Bowen-Conradi syndrome, an inherited genetic disease that causes birth defects and often results in death within the first few months of an infant's life. The syndrome is rare in the general population, but among Hutterites it's estimated that 1 in 335 infants are born with it, according to an article published in the June issue of South Dakota Medicine, the journal of the State Medical Association.
The article said the syndrome is so common among Hutterites that some of them refer to it as the "Hutterite gene." An estimated one in 10 Hutterites is a carrier.
The article referenced two cases of Hutterite infants identified as having Bowen-Conradi syndrome. Both were born with defects. Affected infants tend to have small jaws that prevent them from feeding, shortened muscles or joints, deformed finger joints, small heads and rocker-bottom feet. Heart defects, cleft lip or palate and brain abnormalities can also occur but are not as common. The cause of death is usually failure to thrive because of feeding difficulties.
Diagnosis of children with Bowen-Conradi is based upon family history and physical findings. With a large Hutterite population in South Dakota and the likelihood of confusing the syndrome with a similar disorder known as trisomy 18, it's possible for a doctor to misdiagnose the symptoms, said Dr. Jason Flanagan, genetic counselor at Sanford Maternal-Fetal Medicine Clinic and a main author of the journal article.
Avera Queen of Peace Hospital in Mitchell has not come across Bowen-Conradi, according to Trish Delaney, the hospital's spokeswoman. Doctors at Avera Pediatrics Plus in Mitchell also have not come across the syndrome.
Two tests, which look at chromosomes, are available in the United States to diagnose trisomy 18. But no tests for infants suspected to have Bowen-Conradi are readily available in the United States because the genes must be examined. Genes, a portion of DNA, are bundled together to create chromosomes.
The chromosome tests for trisomy 18 cannot "see" the gene mutation that causes Bowen-Conradi, said Dr. Patricia Crotwell, director of Sanford Clinic USD Genetic Laboratory and contributing author of the study.
"We wouldn't be able to detect babies with Bowen-Conradi because the gene is too small," she said.
The only test that is available is through a research lab in Canada, Flanagan said. The results take eight to 10 weeks and by that time, it's likely the infant will have died.
And without a quicker testing method, there is no definitive way to diagnose an infant with Bowen-Conradi. In the study, the diagnosis of both cases was made by physical appearance. Genetically, there was no way to prove the infants had the condition, Flanagan said.
"A lot of times, individuals just decide not to do that testing to rule out trisomy 18," Flanagan said. "In the past, particularly in the Hutterite population, they elected to let the pregnancy be."
At this point in Bowen-Conradi research, Flanagan doesn't think there is much long-term survival of the affected infants. The first infant in the case study died shortly after being delivered by cesarean section. The second infant died within the first week. The mother of the first infant was recommended to Maternal Fetal Medicine at Sanford Health in Sioux Falls by rural South Dakota doctors.
With the first case, it was the first time Flanagan and some of his colleagues had ever encountered the disease.
The infant looked like it had trisomy 18, but after testing, its chromosomes were normal and trisomy 18 was ruled out.
"I started to do a lot of research to figure out what else it could be," Flanagan said. "Bowen-Conradi kept coming up. It made sense."
By the time the second case arrived, Flanagan and others were up to speed. Now the syndrome is on their radar, even though it's apparently not something commonly diagnosed in South Dakota, he said.
There's a chance that some infants with Bowen-Conradi live longer than suspected. The worst cases are usually the first to be identified by researchers.
"We might have only found the worst-case scenarios," Flanagan said. "It might not be as universally lethal, but as of right now, everything that is known is that it has a short life expectancy."
Exact numbers of how often infants are born with Bowen-Conradi in South Dakota are not known, Flanagan said. South Dakota doesn't have a birth defects registry, so the disease isn't tracked. Flanagan has identified only two cases, both of which are described in the journal article.
"For each individual colony, the chance they have seen the disease is small, but collectively, there are a few babies born with this condition every year in South Dakota," Flanagan said, adding that some cases go undiagnosed.
Hutterites are a communal branch of Anabaptists. Of the roughly 500 Hutterite colonies in the world, about 50 are located in South Dakota and the majority of the rest are in Canada. The total estimated Hutterite population is 45,000.
Colonies in the Mitchell area have little experience with Bowen-Conradi, some colony members said. Some Hutterites, including the women at Oak Lane, had heard of it as the "Hutterite syndrome" and heard it is more common in Canadian colonies.
"It is not unusual for a colony member to not know about the disease," Flanagan said. "There are over 30 common diseases in the colonies and my experience is that the families did not know much prior to their baby being diagnosed."
Mary-Ann Kirkby, a Hutterite by birth who left her colony and later wrote the book "I Am Hutterite," said the syndrome is prevalent among the Lehrerleut Hutterites in Alberta, Canada. Kirkby had also heard of the syndrome occurring in the colonies near Calgary, but not in the South Dakota colonies.
"I know it comes from marrying a distant cousin," said an Oak Lane Hutterite woman. Another Oak Lane woman said if the condition is genetic, it is not in her family line.
The women asked to remain anonymous because of the sensitivity of the topic and what they consider the negative media light shone on Hutterite communities by the ongoing National Geographic Channel television series "American Colony: Meet the Hutterites," which they consider an inaccurate portrayal of their way of life.
Because the Hutterite population is isolated and has less genetic variation, the population suffers from the "founder effect," a term used in population genetics. As intermarriage occurs, the genetic variation decreases significantly. Bowen-Conradi is one of about 30 diseases common in the Hutterite population because somewhere along the line, one person had a mutation of the Bowen-Conradi-causing gene, EMG1.
"If you have one mutation, you're fine," Crotwell said. "You're clinically normal. Since one person had it and there are very few people that gave rise, that mutation was passed down through generations."
Marriages are not arranged in Hutterite colonies. Young Hutterites visit other colonies and "hang out" while getting to know each other.
"We court the same way you do," an Oak Lane Hutterite woman said.
Hutterites are allowed to marry their second cousins, though "some parents are very much against marrying your second cousin," another Oak Lane woman said.
Over time, the chance of two carriers marrying increases. With both parents as carriers, the chance of a child being born with the syndrome is 25 percent.
"It won't stop us from having children, unless a couple ran into three or four [babies with the syndrome]," an Oak Lane woman said.
'In God's hands'
Options are few to prevent Bowen-Conradi. One option is to test all couples to see if they are carriers of the gene, with testing prior to marriage being most effective because it would give the option of not marrying when both the man and the woman are carriers.
For couples who are already married, the only way to prevent the syndrome is in vitro fertilization. That would allow examination of the embryo for the gene mutation. Any normal embryos would be used to conceive or frozen for a potential future pregnancy.
If there were affected embryos that were not used, Flanagan said, that would present a problem for most Hutterites.
"A lot of people struggle with that because of potential moral, religious reasons," Flanagan said. "Technically, that is the only way to prevent it, other than not allowing couples to get married."
Jacob Wipf, a minister at Oak Lane Colony, said he and his wife were tested for diseases before they were married -- it was compulsory.
Wipf said he has thought about genetic testing over the years and he's OK with the testing happening before the marriage and before the couple fall in love.
"Once somebody falls in love, it's hard," he said. "Say the tests say you can't have children because they'll be handicapped. I feel I couldn't make the call for them not to have children. It's God's choice if they have a handicapped child."
But Wipf does not approve of in vitro fertilization.
"We've never allowed it," he said. "Absolutely not."
Flanagan said the Hutterites don't need to be overly concerned, but they should be educated on the risk of having a child with Bowen-Conradi syndrome.
From the Hutterite perspective, it's only one of 30 diseases common among Hutterite descendants.
"Couples from the colonies collectively have a much greater risk for having a child with a severe disease than almost any other population in the world," Flanagan said. "For a colony member, though, they may in fact not want to know what their risk is.
"Or, even if they know the risk is significant, they may leave it in God's hands anyway."