SGS is a complex genetic disorder that typically causes: •a major facial defect called midface retraction, •a disorder known as hydronephrosis caused by obstruction and distension in the kidney, •unusual skeletal features, •excessive growth of bodily hair (hypertrichosis), •seizures, •abnormal EEG, •severe mental retardation, and •failure to thrive. There can also be heart problems, genital abnormalities, and spells of interrupted breathing.
The probable cause is a recessive genetic defect carried by both parents, so that the disease does not show up in the parents and 3 out of 4 of their children (speaking statistically). It is not known what chromosomes carry the defect.
There is no genetic or blood test for SGS. Physical examination of the affected infant, looking for the various features of the syndrome, is the only diagnostic method. Ultrasound could be used to detect the kidney defect, and radiologic diagnosis could be used to detect the skeletal abnormalities.
Treatment is only supportive, and cannot affect the outcome of the disorder. Examples of treatment would be gastrostomy feeding tubes to facilitate feeding, antibiotics for the frequent urinary tract infections, anti-seizure medications to subdue the seizures, and comfort measures such as oxygen, tranquilizers, or pain relievers.