Clinical, morphologic, and biochemical characteristics of Chediak-Higashi syndrome in fifty-six Japanese black cattle.

OBJECTIVE

To characterize Chediak-Higashi syndrome (C-HS) in Japanese Black cattle.

ANIMALS

56 of 200 cattle with a bleeding disorder and giant granules in leukocytes.

PROCEDURE

Clinical observation, CBC, hemostatic screening test, platelet aggregometry, electron microscopy, platelet constituent analysis, and ophthalmoscopic examination were done.

RESULTS

Affected Japanese Black cattle had increased bleeding tendency and abnormal granules in their leukocytes. Susceptibility to infection was not increased. Cutaneous albinism was evident in 6 new-born calves, but not in most affected cattle. In all affected cattle, the tapetal fundus was pale and the nontapetal fundus was almost devoid of pigment. By electron microscopy, a remarkable decrease in the number of dense granules in platelets was observed. Functionally, collagen-induced platelet aggregation was markedly reduced.

CONCLUSIONS

This bleeding disorder was diagnosed as C-HS. With regard to susceptibility to infection, albinism, and mortality, clinical manifestations of C-HS in Japanese Black cattle were moderate, compared with C-HS in human beings and Hereford cattle.

CLINICAL RELEVANCE

Because an autosomal recessive mode of inheritance was documented and recessive homozygotes could be easily detected, C-HS in Japanese Black cattle can be controlled.