Hennekam-Beemer syndrome is characterized by the association of skin mastocytosis (appearing as diffuse pigmentation), short stature, microcephaly, conductive hearing loss, and dysmorphic features. It has been described in only two (female) cases: one with normal mental development born to consanguineous parents and the other with severe psychomotor retardation born to unrelated parents. The mode of inheritance is most likely autosomal recessive.

The palpebral fissure inclination is more than two standard deviations above the mean for age (objective); or, the inclination of the palpebral fissure is greater than typical for age.