Anyone test for G6S?
- Thread starter GLENMAR
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Straw Hat Kikos
The Kiko Cowboy
I have no idea what that is. I don't have Nubians so I hope I'm safe.
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GLENMAR
True BYH Addict
All animals, including dairy goats, have numerous genetic defects of varying severity. We are all familiar with the occasional multiple teats, for instance, and with such defects as undershot and overshot jaws. Other defects are rapidly fatal, and it often is unclear whether the death of a kid should be attributed to genetics or to misfortune. The exact inheritance of many of these defects is often obscure; for instance, although most people believe that multiple teats show up when both parents carry a gene for this trait there is evidence that in some cases they are actually caused by environmental factors. In order to manage these undesirable genes breeders usually have to fall back on the "don't repeat that breeding" strategy, which is very crude and unsatisfactory.
This article will describe a recently discovered genetic defect which is easily managed and eliminated because its mode of transmission is straightforward and, more important, because a foolproof DNA test is available to identify carriers of the gene.
This defect's full names are mucopolysaccharidosis IIID, or G-6-Sulfase deficiency, and it is usually referred to as G-6-S. It was first identified in 1987 at Michigan State University, and subsequently the researchers tested nearly one thousand goats in Michigan and concluded that about 25% of Nubians carry this gene. All cases are the result of a single mutation, and appear to be confined to Nubians and their crosses; other breeds were tested initially and they do not have this particular defect.
The affected goats lack an enzyme (G-6-S) and this results in a variety of symptoms of varying severity. The main symptom exhibited by affected goats is failure to grow. Sometimes the kid is smaller than normal at birth, and grows slowly. Some breeders have reported kids which grew normally for the first three months and then stopped growing. Other affected goats grow to what appears to be normal size but is in fact small for the particular bloodlines. They lack muscle mass, appear "slab-sided", sometimes with blocky heads. Immune function appears to be compromised, and sometimes they become deaf or blind. The longest-lived goat known to be G-6-S affected died at just under four years of age, and death is usually due to heart failure. Unfortunately affected animals can and do grow up to breed, although they often experience reproductive problems.
The same symptoms can have many other causes, so that affected animals are seldom recognized as having a genetic defect. Often they grow normally for the first few months and may be sold before any problems become apparent. In that case the breeder may blame the new owner for the goat's failure to thrive and early demise.
This article will describe a recently discovered genetic defect which is easily managed and eliminated because its mode of transmission is straightforward and, more important, because a foolproof DNA test is available to identify carriers of the gene.
This defect's full names are mucopolysaccharidosis IIID, or G-6-Sulfase deficiency, and it is usually referred to as G-6-S. It was first identified in 1987 at Michigan State University, and subsequently the researchers tested nearly one thousand goats in Michigan and concluded that about 25% of Nubians carry this gene. All cases are the result of a single mutation, and appear to be confined to Nubians and their crosses; other breeds were tested initially and they do not have this particular defect.
The affected goats lack an enzyme (G-6-S) and this results in a variety of symptoms of varying severity. The main symptom exhibited by affected goats is failure to grow. Sometimes the kid is smaller than normal at birth, and grows slowly. Some breeders have reported kids which grew normally for the first three months and then stopped growing. Other affected goats grow to what appears to be normal size but is in fact small for the particular bloodlines. They lack muscle mass, appear "slab-sided", sometimes with blocky heads. Immune function appears to be compromised, and sometimes they become deaf or blind. The longest-lived goat known to be G-6-S affected died at just under four years of age, and death is usually due to heart failure. Unfortunately affected animals can and do grow up to breed, although they often experience reproductive problems.
The same symptoms can have many other causes, so that affected animals are seldom recognized as having a genetic defect. Often they grow normally for the first few months and may be sold before any problems become apparent. In that case the breeder may blame the new owner for the goat's failure to thrive and early demise.
