Chromosome 1 is the designation for the largest human chromosome. This gene is part of a cluster of cytochrome P genes on chromosome 7q22.1. OI caused by homozygous mutation in the SPARC gene on chromosome 5q33. This gene occurs on the X chromosome. X-linked dominant disorders are caused by mutations in genes on the X chromosome. The piebald gene is on a different chromosome. Genes on the same chromosome would theoretically never recombine. The following are some of the gene count estimates of human X chromosome. It is an autosomic recessive disorder caused by a mutation of the chromosome 6. This gene is located on the X chromosome. The Btk gene is located on the X chromosome (Xq21.3-q22). Schwannomatosis is caused by various mutations on chromosome 22. This is partly related to the number of "SMN2" gene copies present on the chromosome. The gene is located on the long arm of the ninth chromosome (9q34). Y-linked disorders are caused by mutations on the Y chromosome.