A male with the 47 XYY syndrome may have a number of clinical findings. Many patients may go undiagnosed.
Common clinical findings include:
(1) tall stature
(2) macrocephaly
(3) macro-orchidism starting with puberty
(4) hypotonia
(5) hypertelorism
(6) tremor
Additonal findings may include:
(1) autism spectrum disorder
(2) macrodontia and/or prognathic jaw
(3) pes planus
(4) central adiposity
(5) clinodactyly
(6) seizures
(7) asthma