Add people one at a time, connect them as parents and children, and see which inheritance patterns fit: autosomal recessive, X-linked, and more.
Click anyone to add their parent, partner, or child
Male
Female
Affected
How the analysis works
Each inheritance pattern makes a specific, testable prediction about who in a family can be affected. This tool checks your pedigree against those predictions for six patterns:
Autosomal dominant. One copy of the allele is enough. Affected people almost always have an affected parent.
Autosomal recessive. Two copies are needed. Two unaffected carrier parents can still have an affected child.
X-linked recessive. Carried on the X chromosome. Affected fathers never pass it to their sons, only to their daughters as carriers.
X-linked dominant. Affected fathers pass it to all their daughters and none of their sons.
Y-linked. Only males are ever affected. It passes from father to every son.
Mitochondrial. Passed only through the mother, to all children regardless of sex.
A pattern is ruled out the moment one relationship in your tree contradicts its rule. Patterns that survive every check are consistent. Small families are often consistent with more than one pattern, and the tool reports that honestly instead of guessing at a single answer.
The genotype table also offers an optional assumption, switched on from the Analyze panel. Turn it on, and anyone who joins the family only by partnership, with no parents recorded in the tree, gets treated as carrying no disease allele at all. This mirrors the standard convention used in teaching pedigree analysis: for a rare trait, someone marrying in from the general population is assumed unaffected and not a carrier, unless the pedigree shows otherwise. It's an assumption, not something the chart proves, so it stays off by default.