The Manx breed is genetically distinct from the Japanese Bobtail breed, another naturally occurring insular breed. The Japanese Bobtail always has at least some tail, ranging from a small "pom" to a stubby but distinct tail, which is kinked or curled and usually has a slightly bulbous and fluffy appearance; by contrast, the Manx has a straight tail when one is present at all. The Japanese Bobtail has a markedly different appearance from the Manx, and is characterized by almond-shaped eyes, a triangular face, long ears, and lean body, like many other Asian breeds. The gene responsible for the bobbed or kinked tail in that breed is recessive and unrelated to the dominant Manx tail-suppression gene; the bobtail gene is not connected to any serious deformities, while the tail-suppression gene can, under certain conditions, give rise to a pattern of sometimes lethal health problems. The Pixie-bob breed also has a short tail, and may be genetically related to the Manx. More will be clear about tail genetics as more genetic studies are done on cat populations and as DNA testing improves; most domestic animal genetic work has been done with dogs and livestock breeds.