Affiliation: | (1) Genetic Services, Department of Health and Welfare, Private Bag X63, 0001 Pretoria, Republic of South Africa;(2) Department Human Genetics, University of Orange Free State, 9301 Bloemfontein, Republic of South Africa;(3) New Hope School, 0002 Pretoria, Republic of South Africa;(4) Department Cytogenetics, Tygerberg Hospital and Medical School, University of Stellenbosch, 7505 Tygerberg, Republic of South Africa |