Hypertrichosis of the ears, webbed toes, and porcupine man are examples of Y-linked inheritance in humans. Hypertrichosis of the ears (or hairy ears) is a condition wherein there is a conspicuous growth of hair on the outside rim of the ear.
Why are there no Y-linked diseases?
Y linkage can be difficult to detect. This is partly because the Y chromosome is small and contains fewer genes than the autosomal chromosomes or the X chromosome. It is estimated to contain about 200 genes. Earlier, the human Y chromosome was thought to have little importance;.
Do Y-linked genes exist?
Y-linked inheritance. Y-linked traits never occur in females, and occur in all male descendants of an affected male. The concepts of dominant and recessive do not apply to Y-linked traits, as only one allele (on the Y) is ever present in any one (male) individual.