RT Journal Article SR Electronic T1 Problem of sex ratio in cases of type I syndactyly. JF Journal of Medical Genetics JO J Med Genet FD BMJ Publishing Group Ltd SP 108 OP 113 DO 10.1136/jmg.14.2.108 VO 14 IS 2 A1 C M Woolf A1 D L Cone YR 1977 UL http://jmg.bmj.com/content/14/2/108.abstract AB Fifty pedigrees of type I syndactyly were analysed for sex ratio and segreation pattern. Thirty-four of the pedigrees were from the published reports; 16 were collected in the State of Utah. Pedigrees with affected individuals showing webbing between the second and third toes are characterized by a sex ratio of affected individuals favouring males and a highly significant excess of affected sons of heterozygous fathers. A similar distorted segregation pattern is present in those pedigrees when the webbing involves the second and third toes and/or the third and fourth fingers, but not in those pedigrees when the webbing involves other digits. The reason for the distorted segregation pattern is unknown. Hypothesis include abnormal chromosome segregation and gametic selection.