Y linkage

In mammals, Y-linkage, also known as holandric inheritance, is the determination of a phenotypic trait by an allele (or gene) on the Y chromosome.

Because the Y-chromosome is small and does not contain many genes, few traits are Y-linked, and Y-linked diseases are rare. Since the only humans who have a Y chromosome are males, Y-linked traits are passed only from father to son, with no interchromosomal genetic recombination.