Curly/wavy coat in Cornish Rex and German Rex

The Cornish Rex and German Rex breeds are characterised by a fluffy curly or wavy coat. This trait is caused by mutation c.250_253del in the LPAR6 gene, which encodes lysophosphatidic acid receptor 6. This is a receptor essential for maintaining the structural integrity of the hair shaft.

Inheritance of the mutation is autosomal recessive. This means that only individuals who inherit the mutated gene from both parents will develop the trait. Carriers of the mutated gene have a straight fur but pass the mutation on to their offspring. If two heterozygous individuals are mated, theoretically 25% of the offspring will have straight hair, 50% of the offspring will be carriers and 25% of the offspring will inherit the mutated gene from both parents and have wavy hair.

References:

Gandolfi, B., Alhaddad, H., Affolter, V.K., Brockman, J., Haggstrom, J., Joslin, S.E., Koehne, A.L., Mullikin, J.C., Outerbridge, C.A., Warren, W.C., Lyons, L.A. : To the root of the curl: A signature of a recent selective sweep identifies a mutation that defines the Cornish rex cat breed. PLoS One 8:e67105, 2013. Pubmed reference: 23826204