X-linked dominant pedigree software

Classical XLD assumes similar severity in heterozygous females and hemizygous males. In practice, the clinically encountered X-linked dominant disorders split into five observable live-born patterns — and the correct recurrence-risk number turns on which pattern applies. Evagene models all five.

The five sex-differential severity sub-modes

Equal
Classical

Similar severity in both sexes. The textbook XLD description.

Males worse

Males substantially more severely affected than heterozygous females; both sexes viable.

Male-lethal, reproduces — 1:1:1 live-born ratio

Affected males are not live-born. Carrier-mother offspring split 1 affected daughter : 1 unaffected daughter : 1 unaffected son. Canonical: incontinentia pigmenti (IKBKG), focal dermal hypoplasia (PORCN), OFD1.

Male-lethal, no reproduction

Affected males not seen in live births or recorded offspring. Canonical: Rett syndrome (MECP2), CDKL5-related disorder.

Metabolic-interference, males unaffected

Males phenotypically spared. Canonical: craniofrontonasal syndrome (CFND, EFNB1), Epilepsy and Mental Retardation Limited to Females (EFMR, PCDH19).

Offspring risk — sex-split and sub-mode-aware

For each sub-mode, Evagene's risk engine produces sex-specific offspring probabilities calibrated to what the clinician should expect to count in the live-born generation. The sub-mode is stored on the disease record and pre-populated for canonical disorders through catalogue lookup.

Who this is for

Clinical geneticists, genetic counsellors, and reproductive-medicine specialists. The classical consultation — a woman whose sister has had multiple daughters affected by a Rett-like picture and no affected sons — resolves differently under the male-lethal-no-reproduction sub-mode than under textbook XLD.

See also

Model the XLD pattern that actually fits

Free access during Alpha.

Join the Alpha Waiting List