Laminin alpha2-deficient muscular dystrophy is a genetic disease in cats, although the genes responsible for the laminin alpha2-deficiency are yet to be identified and characterised.
Laminins are large glycoproteins that make up the basement membranes in a variety of tissues including muscle and Schwann cells. Although named muscular dystrophy, this syndrome actually involves nerves and muscles. In peripheral nerves, deficiency in Laminin alpha-2 affects the Schwann cells ability to form myelin and results in a hypomyelinating neuropathy.
This disorder has been described in two cats, a DSH cat and a Siamese cat. Both were female cats that were presented around 12 months of age for progressive weakness. Extensor contracture was a prominent feature in the DSH cat, whereas the Siamese was hypotonic and hyporeflexive in all four limbs. Both cats had marked increases in serum creatine kinase values, and motor nerve conduction velocities were reduced in the one case evaluated (the DSH). Dystrophic changes were present in all muscles evaluated, and demyelination of peroneal and radial nerves was noted. Immunocytological evaluation of muscle fibres showed decreased or absent laminin alpha-2. Both cats were euthanized within months of diagnosis.
Because of the poor prognosis, treatment is usual not recommended in the long-term, although palliative care (symptomatic) is as option.
1. August, JR (2006) Consultations in Feline Internal Medicine, Vol 5. Elsevier Saunders