Family Association Tests

Use this parameter to specify the type of family-based association tests to be performed using SAS PROC FAMILY.

Family genotype data, though difficult to collect, often provide a more effective way of testing markers for association with disease status than case-control data. Case-control data can uncover significant associations between markers and a disease that could be caused by factors other than linkage , such as population structure. Analyzing family data by using the SAS FAMILY procedure ensures that any significant associations found between a marker and disease status are due to linkage between the marker and disease loci . This is accomplished by using the transmission/disequilibrium test ( TDT ) and several variations of it that can accommodate different types of family data.

Available tests are described in the following table:

Test	Description
TDT	Uses the original TDT test. This procedure is suitable for families with parents, at least one heterozygous , and an affected child who have all been genotyped
STDT	This procedure is suitable for families having at least one affected and one unaffected sibling from a sibship that have both been genotyped.
SDT	This nonparametric procedure is suitable for families having at least one affected and one unaffected sibling from a sibship that have both been genotyped.
RCTDT	Both types of families can be jointly analyzed using the combined versions of the S-TDT and SDT and the reconstruction-combined TDT (RC-TDT). The RC-TDT can also accommodate families with no unaffected children and missing parental genotypes in certain situations

The TDT test is selected by default. If none of the tests are specified, all are performed.

To Choose One or More Association Tests:

Left-click on a single test, or press and hold Ctrl while left-clicking on multiple tests.

For More Information:

Refer to the SAS PROC FAMILY documentation for additional details.