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Mannosidosis
(MA)
Return to Genetic Defects
About Mannosidosis
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The Condition
The History
The Genetics
The Policy
Testing
Questions and
Support
Tested Animals
The Condition
Alpha Mannosidosis (MA) is an inherited condition in beef cattle
that affects the nervous system. In affected animals the Alpha
Mannosidosis enzyme does not work optimally to break down sugars
in lysosomes causing a buildup of sugars and deterioration of
the central nervous system. Like AM, NH and OS this condition is
fatal, however, symptoms do not normally develop until the
animal reaches sexual maturity. At about yearling age affected
animals develop head tremors, loss of muscle control and
difficulty walking, aggression issues, failure to thrive, and
ultimately die.
The History
MA is one of the oldest genetic defects known in beef cattle.
The Australian Angus Association undertook an aggressive
endeavor to eradicate the gene from their herdbook in the 1980s
after several Australian calves were diagnosed with MA. Much of
what we know about MA today is a result of their research and
efforts. Calves affected by MA have been documented in several
countries including Scotland and America, and in several
different beef breeds including Aberdeen Angus, Galloway and
Murray Grey.
The Genetics
Similar to AM, NH and OS, the gene that causes Alpha
Mannosidosis (MA) is a recessive gene, requiring two carrier
parents to be bred before an affected calf is ever seen. To date
there have been no reports of an affected calf in Canada. The
frequency of the recessive gene in the Canadian herdbook is
minimal. However, carrier animals, which look normal, can still
pass on the gene to future generations. A DNA test has been
validated in North America so that these carrier animals can be
identified.
The Policy
The Canadian Angus Association has a genetic defect policy in
place designed to control and eliminate the frequency of
undesired genes in the Canadian Angus herdbook. The policy
states that any animal with a known carrier of a genetic defect
(including MA) in the first two generations (parental and
grandparental) of its pedigree, without an intervening free
test, must be tested for the defect to be eligible for
registration.
Commencing January 1st, 2011 any animal that is
tested and found to be a carrier of the recessive gene that
causes MA will not be eligible for registration. It is not
recommended that these animals be marketed or used for breeding.
Testing
DNA testing is for MA is available at an economic fee of $26 and
can be requested by completing the
Genetic Defect Test Request Form. The test results will be
indicated on our website and on the animal registration
certificates where MAF will indicate that the animal has been
tested free of the causative gene and cannot pass it on to
further generations. MAC will indicate that the animal has been
DNA tested and found to be a carrier of the gene that causes MA
and will pass it on to 50% of its progeny. If bred to another
carrier, the animal will have 25% normal non-carrier calves, 50%
normal looking but carrier calves, and 25% affected calves.
Questions and Support
Please do not hesitate to contact Kajal Devani at 1-888-571-3580
or by email if you have
any questions in regards to MA or any other genetic defect.
Tested Animals
MA Carrier Animals
MA Tested Free Animals
Lists last
updated July 20, 2010
Page updated April 6, 2010 |
