X chromosome | Y chromosome | Philadelphia chromosome | polytene chromosome | Human Y-chromosome DNA haplogroup | An inversion loop in the A arm of a chromosome from an ''Axarus |
A Pitt–Hopkins like phenotype has been assigned to autosomal recessive mutations of the contactin associated protein like 2 (CNTNAP2) gene on the long arm of chromosome 7 (7q33-q36) and the neurexin 1 alpha (NRXN1) gene on the short arm of chromosome 2 (2p16.3).
In 1998, Simon Fisher and colleagues identified a small section of chromosome 7, dubbed SPCH1, which was linked to the speech and language disorder in this family.