Kidneys Individuals with Okamoto syndrome are usually born with
hydronephrosis, or dilation of the internal structures of the
kidneys, due to narrowing (
stenosis) of the passage between the kidneys and the
ureters (the ureteropelvic junction), leading to a build-up of urine. There is also often
vesicoureteral reflux, in which urine passes backwards from the
bladder to the ureters, and frequent
urinary tract infections.
Heart Individuals with Okamoto syndrome are typically born with
heart defects, which can include
aortic valve stenosis,
atrial or
ventricular septal defect,
bicuspid aortic valve or
patent ductus arteriosus.
Physical features The syndrome has a characteristic facial appearance which is similar to that of
Kabuki syndrome, including prominent,
downward-displaced ears that are underdeveloped, long eyelids,
epicanthic folds, a short, broad nose, an open, downturned mouth and a deep groove in the midline of the tongue.
Cleft palate occurs in about half of those affected. There is sometimes
webbing of the neck or
bulging eyes, and less commonly there is
excessive hair on the forehead or other parts of the body or a
unibrow. Individuals with the syndrome may also have a broad first toe and crowding of the toes, and at least two affected individuals have had polydactyly of the fifth digit (
postaxial polydactyly). Some of those affected have had
undescended testicles (cryptorchidism). A small minority of those affected have had
congenital joint contractures such as
club foot.
Neurological Those with Okamoto syndrome typically have severe mental disability and are usually born with
microcephaly. There are typically language and walking delays, and those affected have very
low muscle tone and
decreased reflexes. They may have
neural tube defects such as
lipomyelomeningocele (a form of
spina bifida) or may have
syringomyelia (a cyst in the spinal cord). Those with the syndrome may also have symptoms of
dysautonomia (impairments in the
autonomic nervous system), including
gastrointestinal dysmotility, contributing to
gastroesophageal reflux disease, or
neurogenic bladder dysfunction, in which bladder control is limited. Dysautonomia has also led to high pain tolerance and
reduced sweating in some patients. Some of those with the syndrome have been found to have an
underdeveloped corpus callosum, the main band of
white matter that connects the two
cerebral hemispheres.
Skeletal Okamoto syndrome patients often have skeletal problems such as
scoliosis or
hip dysplasia, which can lead to
hip dislocation. They may be born with
congenital vertebral anomalies; parts of the spine may be fused and fail to segment. There may also be extra vertebrae in the
lower back. Some of those affected have been reported to have premature fusion of the skull bones (
craniosynostosis), particularly those across the
midline and at the
front of the skull. This has led to an elongated skull shape known as
scaphocephaly as well as a ridge on the forehead known as a
metopic ridge.
Growth Those affected may be born with
low weight and size and may display stunted growth in childhood, although this symptom has been variable and not in every individual with Okamoto syndrome.
Hearing and eyesight A minority of those with Okamoto syndrome have had hearing loss of both
sensorineural and
conductive types, and a smaller minority have had
optic nerve abnormalities. == Cause ==