Thursday, December 13, 2012

Consanguinity


Consanguinity ("blood relation", from the Latin consanguinitas) refers to the property of being from the same kinship as another person. In that respect, consanguinity is the quality of being descended from the same ancestor as another person. The laws of many jurisdictions set out degrees of consanguinity in relation to prohibited sexual relations and marriage partners. 

The offspring of consanguinous relationships are at greater risk of certain genetic disorders. The extent to which the risk increases depends on the degree of genetic relationship between the parents; so the risk is greater in mating relationships where the parents are close relatives.

Consanguinity: con·san·guin·i·ty [kon-sang-gwin-i-tee–noun
The condition of being of the same blood; relationship by descent from a common ancestor; blood-relationship.
- Oxford English Dictionary

Children of Incest

J Pediatr. 1982 Nov;101(5):854-7.

Twenty-nine children of brother-sister or father-daughter matings were studied. Twenty-one were ascertained because of the history of incest, eight because of signs or symptoms in the child. In the first group of 21 children, 12 had abnormalities, which were severe in nine (43%). In one of these the disorder was autosomal recessive. All eight of the group referred with signs or symptoms had abnormalities, three from recessive disorders. The high empiric risk for severe problems in the children of such close consanguineous matings should be borne in mind, as most of these infants are relinquished for adoption.


Placing a Child for Adoption

Women have varying and often deeply personal reasons for placing their biologic children for adoption. Common reasons for being unable to retain parental rights include:
·         serious drug or alcohol abuse problems
·         extreme youth or immaturity
·         pregnancy that was the result of rape or incest
·         health or disability issues that prohibit properly caring for a child\



Incest Inadvertently Revealed By DNA Analysis

Analyzing children's DNA to diagnose developmental disabilities and congenital anomalies can inadvertently reveal that some were conceived through incest.  

Because of developments in genome technology, and because that technology is now more affordable, doctors are now increasingly able to scan the genomes of individual children to look for missing or duplicate sequences of DNA code.

In children born from incest, their genomes show an "absence of heterozygosity", reflecting the fact that their DNA contains large chunks where the mother's and father's contribution are identical, because they themselves shared much of their genetic code. The more chunks of the child's DNA that show the mother's and father's contribution are identical, the more likely it is that they are first degree relatives, such as father and daughter, mother and son, or brother and sister.

Identification of incestuous parental relationships by SNP-based DNA microarrays."
CP Schaaf, DA Scott, J Wiszniewska, AL Beaudet
The Lancet, Vol. 377 No. 9765 pp 555-556, published online 12 February 2011.
DOI:10.1016/S0140-6736(11)60201-8


Subject:           Hello
Date:                12/13/2012 12:05:36 P.M. Central Standard Time
From:               esanborn@mail.rockefeller.edu
To:                   Cfutia@aol.com

Hi Mrs. Futia,

Hope you are all having a healthy and happy holiday season! I wanted to update you on Peter's testing. We finally have all of the data back from the whole exome sequencing that was run. Our lab head is in the process of analyzing the data. As you can imagine the test we ran produces a lot of information. The interpretation process is more involved for individuals where we cannot study multiple biological family members at the same time as it is difficult to determine which genetic changes are benign and which might be responsible for the struggles that Peter has. Does that make sense?

If something "obvious" comes from the interpretation phase I would probably be in touch in the next month about that. The more likely scenario however, is that we will have "hits" or clues from the analysis that we need to do more functional testing on to see if they are benign or not. This is usually done 1 or 2 genes at a time so can take another few months to be honest. Given we finally had his data back I just wanted to update you with as much information as I had.

I also wanted to ask a few questions that might aid in the analysis process. When we had originally spoken, you said you didn't know a lot of information about his birth parents...is that correct? Through our analysis we can see that Peter has many, many areas of his genetic information that are the same on both copies of his genes (one copy he got from mom and one copy he got from dad). This would suggest that his biological parents were close blood relatives to each other. Do you have any information about this or records that we might be able to ask for through the orphanage? We understand this might not be possible but thought it wouldn't hurt to ask.

Thank you again for your participation and patience. While we are not crossing the finish line just yet, we are many steps closer than the last time we spoke.

Erica Sanborn, MS, CGC
Rockefeller University



Subject:           Re: Hello
Date:                12/13/2012 2:06:41 P.M. Central Standard Time
From:               Cfutia@aol.com
To:                   esanborn@mail.rockefeller.edu

Dear Erica,

I have long suspected consanguinity as the underlying cause of Peter's telomere disorder. For one thing, consanguinity is high in many small castes, tribes or communities all across India. Putting it another way, India is one of the world's hotbeds of consanguinity. But more significantly, what little information we have on Peter's birthfamily is very suggestive of consanguinity.

Worldwide, incest has always been one of the reasons why babies are placed for adoption. In India, such children would often be abandoned, or handed off to a third party for disposal. When orphanage workers did interact with birthmothers, they traditionally took an “ask no questions” stance.  Any information that did emerge would most often go unrecorded. 

Our family has three children who were adopted from Calcutta.  Two were abandoned, and one – Peter – was relinquished shortly after birth. The older two came with no information whatsoever.  In Peter's case, there is one document, a relinquishment certificate, that provides a tiny bit of insight into his background.. His birthmother was said to be 27 years old, single and living at home with her parents. The form gives her father’s name, and (I believe) his signature.  The birthmother herself signed with a thumbprint.

No one at the orphanage remembers where the relinquishment took place, as the social workers involved are long gone and the relinquishment document does not provide this information. The family’s address was recorded as "Serampore". That's like saying "Houston". The family's last name is "Das" -- like "Smith" or "Jones" in that part of India.  So no tracing is possible, and that's a tragedy from many points of view, not least from Peter's, since he would give anything to meet his birthmother just once.

Now here's the thing that has always stuck in my mind.  Peter’s birthmother was clearly illiterate, and most likely from a community where girls are typically married off as soon as possible after puberty. It is very unusual for an able-bodied woman of 27 to be single and living at home. This suggests to me that she may have been handicapped in some way -- physically, intellectually, emotionally?

It’s possible she might have been married and then sent back to her parents by her husband's family, and later divorced. But my gut tells me that she may not have been marriageable. Perhaps she also had DC, with the same small head and mental retardation that we see in Peter.  Or perhaps she suffered from mental illness, as Peter does from acute early-onset bipolar disorder.

The supposition of incest is a leap, but not a large one. A young woman of 27, unmarried and living at home, gives birth to a child with a rare genetic syndrome.  DNA analysis reveals that his biological father was closely related to his mother.  Well goodness, what do we THINK happened?  This has been my hypothesis from the moment we learned that Peter had DC.

I wish I could give you hard information instead of supposition, but unfortunately, this is all we have.

Even though it makes no difference to the outcome, I can’t wait to find out what gene is implicated in Peter’s DC.  Whether it takes a month or six or twelve, at least we’re on the road.

Regards,

Chris

P.S. I'm attaching a recent photo of Peter, taken a few weeks before he turned 18 in October.