General Medical Information

Incomplete Müllerian Fusion

Joe Leigh Simpson

Familial aggregates of incomplete müllerian fusion include multiple affected siblings, as well as affected mother and daughter. In some families, affected relatives show different forms of incomplete müllerian fusion.

The only one formal genetic study is that of Elias, who found only one of 37 (2.7%) sisters of probands to have a clinically symptomatic uterine anomaly; no (0/24) mothers, no (0/44) maternal aunts, and no (0/50) paternal aunts were affected. The prevalence of 2.7% in siblings should be considered a minimum frequency, because relatives might have a minor uterine anomaly in asymptomatic form. If female relatives have not attempted pregnancy, the opportunity to manifest symptoms that would suggest an anomaly would be limited. Performing hysteroscopy, hysterosalpingography, or laparoscopy on relatives would be ideal but impractical. Even with these inherent limitations, however, the likelihood of first-degree female relatives being similarly affected with müllerian fusion anomalies would seem too low to be compatible with autosomal dominant or autosomal recessive etiology.

That approximately 3% of female siblings were affected in the one formal study is most consistent with predictions based on polygenic/multifactorial etiology.