Schinzel-Giedion Syndrome
Definition
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.
Description
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 impairment.
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.
Genetic profile
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.
Demographics
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 mid-face 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 mid-face, 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.
