These defects are: mannosidosis, rejected by causing deformity at the skull and face (JOLLY, 1993); gangliosidosis, but the signs of this disease should include absence of response to external stimulus and slow mastication and deglutition (JOLLY, 1993); cerebellar
abiotrophy, but the histological findings include loss of the Purkinge cells (DE LAHUNTA, 1990); hereditary neurodegeneration, but it is a recessive mutation linked to the sex, occurring only on males (GEORGE, 2002); calves's hereditary ataxia, but histological examination reveals aplasia of the cerebellum neurons (GEORGE, 2002).