Categories: Limbs / fins / digit / tail phene

Mendelian trait/disorder: yes

Mode of inheritance: Autosomal recessive lethal

Disease-related: yes

Key variant known: no

History: Waters and Bywaters (1943) reported a wingless mutation in the White Leghorn breed in the USA. By 1956, this mutation had been lost (Zwilling, 1956). Fortunately, as also reported by Zwilling (1956), "Recently a wingless mutation was found in one of our flocks at Storrs. This seems to be very much like the original mutation." This second mutation became known as wingless-2, and is documented in a separate OMIA entry: OMIA 001547-9031.

Inheritance: Waters and Bywaters (1943) reported pedigree and other evidence that enabled them to conclude that "The wingless abnormality is inherited as a simple autosomal recessive."

Clinical features: As reported by Waters and Bywaters (1943), "The wingless chicks were either completely devoid of both wings or had vestigial wing appendages on one or both sides . . . . In addition to the wingless condition, the lungs, air sacs, and kidneys were partially or completely absent . . . . The rear appendages showed numerous deviations from normal. The down plumage of all wingless embryos was abnormal. The abnormal embryos were apparently equal in size to their normal sibs. The defect may be observed as early as the fourth day of incubation. Many of the embryos are still alive at the end of the 21st dav of incubation." As summarised by Zwilling (1956): "A study of the early embryonic stages of homozygotes (Zwilling, ’49) revealed that the wing buds were relatively normal during the early part of the third day of development but that there was a loss of an ectodermal ridge from the distal edge of the limb bud during the latter part of the third day and during the fourth day. At the end of the 4th day there was no trace of the apical ectodermal ridge in the wing buds of homozygotes."