Synonyms: Lujan-Fryns Syndrome, X-linked mental retardation with Marfanoid habitus, OKS
Chromosome: Xq13
Gene affected: MED12 with p.Asn1007Ser
Inheritance: X-linked
Clinical features:
(1) The condition affects male offspring of heterozygous female carriers.
(2) intellectual disability with mental retardation
(3) hypotonia
(4) enlarged head (macrocephaly, occipitofrontal head circumference > 75th percentile)
(5) Marfanoid habitus, with tall, thin body (height > 75th percentile)
(6) long hands with hyperextensible digits
Facial features
(1) long, thin face
(2) hypernasal speech
(3) high nasal root
(4) high, narrow palate
(5) short philtrum
(6) micrognathia with dental crowding
(7) maxillary hypoplasia
(8) hypotelorism
Other findings:
(1) dysgenesis of the corpus callosum
(2) hyperactivity, attention-seeking, or other behavioral problems
(3) variable history of seizures
