A proband variant is assigned the category HasUnknownX if all of the following are true:

  • The proband is male.

  • The variant is on the X chromosome.

  • The variant is hemizygous (non-reference).

  • The father's genotype at this variant's position is hemizygous reference.

  • The mother's genotype does not include the proband variant's allele.

  • The variant's functional annotations include at least one in unknown_x_functional_types.

  • The frequency of the proband's minor allele is less than unknown_x_max_population_allele_frequency.