Besser et al. (1990) reported a congenital syndrome of long, thin limbs, severe joint and tendon laxity, microspherophakia, ectopia lentis, heart murmurs and aortic dilatation in 7 calves, where all sired by a single phenotypically normal bull suspected of germline mosaicism for a new mutation resulting in this disease. One of the calves died with ruptured aorta at age 16 months. Histopathologic and electron microscopic studies of the aortic media of these calves demonstrated disorganized elastin and narrowed elastic lamina separated by widened spaces. Parsons et al. (1992) with biochemical analyses on two calves with bovine Marfan syndrome showed that in contrast to elastin, collagen in aortae of Marfan calves was significantly higher than the mean of several controls These authors concluded that the microscopic and biochemical lesions of aortic elastin in bovine Marfan syndrome is likely due to defective microfibrillar metabolism. Absence of cystic medial necrosis in bovine Marfan aortae may explain normal elastin content in the animal model. Potter et al. 1993 reported that Bovine Marfan syndrome is closely related to its human’s counterpart in its clinical signs and pathological lesions, suggesting similar metabolic defects for its cause. Major manifestations include ectopia lentis and aortic dilatation, aneurysm, and rupture. Similar to humans, affected cows have a defect in fibrillin metabolism (Potter et al. 1994). Potter et al. 1993 suggested that the bovine Marfan syndrome, like the human disorder, is caused by a mutation in fibrillin, leading to defective microfibrillar synthesis (Mohammad Shariflou 6/11/2006).
