The Samoyed (/ˈsæməjɛd/ SAM-ə-yed or /səˈmɔɪ.ɛd/ sə-MOY-ed; Russian: Самое́дская соба́ка or Самое́д) (also known as the Bjelkier) is a breed of large herding dogs with thick, white, double-layer coats. They are related to the laika, a spitz-type dog. The breed can be affected by a genetic disease known as Samoyed hereditary glomerulopathy, a kidney disease. The disease is known to be caused by an X-linked dominant faulty allele and therefore the disease is more severe in male Samoyeds. Also known as hereditary nephritis, it is caused by a nonsense mutation in codon 1027 of the COL4A5 gene on the X chromosome (glycine to stop codon), which is similar to Alport's syndrome in humans.