Syndrome (PWS) is an inherited disorder genetic disorder which
is generally caused by a deletion in Chromosome 15. The features
of this disorder includes short stature, mental retardation or
learning disabilities, incomplete sexual development, characteristic
behavior problems, and an insatiable appetite. The syndrome was
first described in 1956 by Drs. Prader, Labhart, and Willi.
The following is an overview of characteristics common to Prader-Willi
Syndrome. However, not all symptoms are present in all individuals
and the intensity of characteristics varies from person to person.
Craniofacial Anomies which include; almond-shaped eyes, narrow-bifrontal
diameter, strabismus and early dental caries/enamel hypoplasia.
Feeding problems in infancy with need for special feeding techniques
and poor weight gain/failure to thrive.
or rapid weight gain after 12 months of age but before 6 years
of age resulting in obesity and an obsession with food.
Developmental delays in a child younger than 6 years of age with
mild to moderate mental retardation or learning problems in older
Genital hypoplasia - for males, scrotal hypoplasia, cryptorchidism,
small penis and/or testes for age. For females an absence or severe
hypoplasia of labia minora and/or clitoris.
Sexual maturity not fully developed. The child with PWS will begin
puberty, but not complete it. This results in delayed or incomplete
gonadal maturation with delayed pubertal signs in the absence
of intervention after 16 years of age. In males, small gonads,
decreased facial and body hair, lack of voice change and in females,
amenorrhea/oligomenorrhea after aged 16. This is known as 'precocious
puberty' there will be a development in body hair, some breast
development in girls and a degree of penile development in boys.
Menstruation is often scanty and irregular.
disturbance or sleep apnoea.
Hypopigmentation - fair skin and hair compared to family.
Eye abnormalities (esotropia, myopia).
Small hands and/or feet for height age.
Some disorders have similar symptoms. The clinician, therefore,
in his diagnostic attempt, has to differentiate against the following
disorders which need to be ruled out to establish a precise diagnosis.
To Be Identified
May be associated
with environmental factors however current research has shown
that the PWS results mainly from one of 4 different genetic abnormalities.
deletion on chromosome 15.
15 maternal disomy.
of chromosomes involving chromosome 15.
in the imprinting of Chromosome 15.
There is no cure for PWS
therefore early diagnosis gives parents an opportunity to manage
their child's diet and avoid obesity and its related problems
from the start. However for children with this disorder it is
best to take the multidisciplinary approach and involve the specialties
offered by Pediatrics, Neurology, Endocrinology, Ophthalmology
and Psychotherapy [ See
Therapy Section ]:
infants will benefit greatly from these early interventions with
a with appropriate therapists who can help set up a program to
encourage development and provide assistive devices which will