Disorders of the Endocrine Glands in Relation to Pregnancy.

incidence with cases often arising from cousin marriages of unaffected members, who can be given no assurance that they will not transmit the disorder. On an average one of every four children will be affected. Peroneal muscular atrophy, the cerebromacular degenerations, torsion spasm, albinism, hepatolenticular degeneration, and some myopathies may show this mode of heredity. Leber's optic atrophy is amongst the disorders which show a sex-linked recessive tendency, being chiefly found in male members of affected families. When not sex-linked, it tends to appear in early adult life in males, but near the menopause in female subjects. Epilepsy follows no regular genetic pattern, although a positive family history of fits is not infrequent if carefully looked for, and this can be correlated with a high incidence of electroencephalographic abnormalities in the families of epileptics. Additional non-genetic factors undoubtedly play an important part in the actual production of epilepsy. Russell Brain (24), whose review of the genetics of neurological disorders is a mine of valuable information freely drawn on above, states that approximately one in ten of the children of an epileptic is affected by the disorder. In the absence, however, of a family history of fits, the risk of direct transmission appears to be statistically small, though again probably raised by consanguineous parentage.