The answer is complicated. The molar pregnancy which CHM13 was made from had two copies of one man's X chromosome and, separately, the project sequenced another man's Y chromosome.
The genome’s Y chromosome came from Peshkin, and the rest of the DNA sequenced by the Telomere-to-Telomere (T2T) Consortium comes from a so-called molar pregnancy, a uterine growth that results on rare occasions when a sperm enters an egg that has no chromosomes. The fertilized cell can copy the sperm’s 23 chromosomes, creating two identical sets, and begin to replicate.
The question remains open of whether the owner of CHM13’s genome could be identified using public DNA sequences in genealogy databases. Phillippy thinks not because CHM13’s genome only represents one-half of that person’s DNA. Even if it were possible, NHGRI officials argue it would be unethical to reveal him for any reason, including to get consent.
Because CHM13 has an X chromosome but no Y, the T2T Consortium added Peshkin’s DNA
