Autosomal dominant
Caused by changes in the PLCB4 gene, which acts in a signalling pathway that shapes the lower face in early development. It is mainly described as dominant, with one changed copy that can be inherited or new, and recessive inheritance has also been reported.
Signs and symptoms
The most typical feature is a 'question mark' ear, with a notch or cleft between the upper ear and the lobe. The lower jaw is small, and the jaw joint (mandibular condyle) is underdeveloped, which can affect chewing and mouth opening. Many infants have breathing or feeding difficulties. Less often there are a small mouth and hearing loss. Features vary widely, even within a family.
What a diagnosis changes
Newborns may need assessment of the airway and feeding. Hearing testing, orthodontic and jaw surgery, and ear reconstruction are offered as needed. Genetic counselling helps clarify the inheritance pattern and recurrence risk for the family.
Genes analysed
Also known as
ARCND2; Auriculocondylar syndrome 2; auriculocondylar syndrome caused by mutation in PLCB4; Auriculocondylar syndrome type 2; PLCB4 auriculocondylar syndrome
