Schinzel-Giedion syndrome, or Schinzel-Giedion Midface-Retraction syndrome is a rare malformation syndrome characterized by skeletal anomalies, a coarse face, urogenital defects, and severe mental retardation.
In affected individuals, the ureter, or tube that carries urine from the kidney into the bladder, is obstructed causing the pelvis and kidney duct to become swollen with excess urine. This is called hydronephrosis. Other features of the syndrome include hypertrichosis or the excessive growth of hair, a flat midface, abnormal brain activity, skeletal abnormalities, and severe mental retardation.
Patients show abnormal bone maturation including broad and dense ribs and short arms and legs. Severely delayed mental and motor development is accompanied by seizures and spasticity.
Some scientists have suggested that the syndrome is inherited as an autosomal recessive trait because they observed that the syndrome appeared in two sibs of different sex, which suggested autosomal-recessive inheritance . However, other researchers have hypothesized that Schinzel-Giedion syndrome may be a dominant disorder with gonadal mosaicism in one parent. Gonadal mosaicism can occur when either the testes or ovaries contain some cells with an extra chromosome. Scientists have also postulated that the syndrome may be caused by an unbalanced structural chromosome abnormality.
Schinzel-Giedion syndrome is extremely rare and remains incompletely defined. About 25 to 30 well-documented cases have been reported beginning in 1978. The syndrome was originally observed in a brother, who lived less than 24 hours and a sister who survived for 16 months. Both displayed multiple skull abnormalities and profound midface retraction. They each had congenital heart defects , hydronephrosis, clubfoot , and hypertrichosis. Eight other cases, all sporadic, including two offspring of consanguineous parents were subsequently identified that year. Less than 30 cases are described in the medical literature detailing major and minor features of the syndrome. Only one case has been described in Japan. The other described cases have occurred in Western countries.
Signs and symptoms
Clinical signs include a flat midface, low set ears, a prominent forehead, skull abnormalities including large fontanels or openings, a short broad neck, genital malformations, congenital heart defects including atrial septal defect, clubfoot, and growth retardation.
The detection of renal defects using prenatal ultrasound is one of the primary means of diagnosis. Clinical observation of coarse facial features, skeletal anomalies, and MRI studies aid diagnosis after birth. Serial cranial MRI studies that show a progressive neurodegenerative process affecting both gray and white matter typify Schinzel-Giedion syndrome. Clinical signs of abnormal cortical gray matter include seizures, dementia , and blindness in some cases. Abnormalities in the white matter can produce spasticity and hypereflexia.
Treatment and management
MRI studies indicate the syndrome is a progressive neurodegenerative process and patients have a limited life span. Nursing care and supportive measures are required to keep the patient comfortable.
Death prior to the second year of life represents the most common outcome.
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McPherson, E., et al. "Sacral Tumors in Schinzel-Giedion Syndrome." (Letter) American Journal of Medical Genetics 79 (1998): 62-63.
Schinzel, A., and A. Giedion. "A Syndrome of Severe Midface Retraction, Multiple Skull Anomalies, Clubfeet, and Cardiac and Renal Malformations in Sibs." American Journal of Medical Genetics 1 (1978): 361-375.
Shah, A.M., et al. "Schinzel-Giedion Syndrome: Evidence for a Neurodegenerative Process." American Journal of Medical Genetics 82 (1999): 344-347.
National Organization for Rare Disorders (NORD). PO Box 8923, New Fairfield, CT 06812-8923. (203) 746-6518 or (800) 999-6673. Fax: (203) 746-6481. <http://www.rarediseases.org>.
"Entry 269150: Schinzel-Giedion Midface-Retraction Syndrome." (Last edited 5-12-99). OMIM—Online Mendelian Inheritance in Man.<http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=269150>.