Determining the Paternity Index With the Mother Unavailable

Description

Sometimes the mother is unavailable for paternity studies. In these situations it is still possible to calculate a paternity index from the genetic studies on the alleged father and the child. The paternity index in such cases depends only on the matching frequencies for fragment size(s) or alleles shared between the alleged father and the child.

In testing for an allele or restriction fragment:

(1) presence of 1 band for an individual indicates homozygous

(2) presence of 2 bands for an individual indicates heterozygous

(3) presence of no bands indicates azygous

Alleged Father	Child	Shared Bands	Paternity Index
homozygous	homozygous	share band	1 / q
homozygous	heterozygous	share 1 band	1 / (2 * q)
heterozygous	homozygous	share 1 band	1 / (2 * q)
heterozygous	heterozygous	share 1 band	1 / (4 * q)
heterozygous	heterozygous	share 2 bands	(1 / (4 * p)) + (1 / (4 * q))
any	any	none shared	1

where:

• p and q are the population frequencies for the alleles or restriction fragment

In general:

paternity index >= 1 / (4 * (probability for the shared allele))

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Description

Specialty

ICD-10