الفهرس 
REVIEW OF LITERATUREOnly 14 pages are availabe for public view
 |  | from | 88 |  |  |
| | | from | 88 | | |
Abstract
Microdeletion syndromes are a diverse group of genetic diseases that cannot be detected by routine cytogenetic analysis methods and include a large variety of clinical disorders according to location and size of microdeletion.
Williams syndrome (WS) is a unique type of microdeletion syndromes that causes a wide spectrum of multisystemic clinical manifestations. Its incidence is somewhere between 1 in 7500-20000 livebirths. It is caused by chromosome 7q11.23 that can be detected by FISH technique that is the gold standard for its diagnosis. Most cases are sporadic, but some studies had mentioned familial autosomal dominant inheritance in some few cases.
This study was conducted on twelve patients that were suspected clinically to have WS but unfortunately one patient had died during the study, and he did not have FISH testing.
In current study, Patients were subjected to:
1- Taking full clinical history including personal, developmental, family, medical and surgical history. Three generations pedigrees were constructed emphasizing on presence of consanguinity and its degree.
2- Complete physical examination including anthropometric measurements (Weight, height, and head circumference), detection of dysmorphic facial features, chest, abdominal and nervous system examination.
3- Echocardiography was done for diagnosis of different congenital heart diseases that are frequently present in WS patients, assessment of their severity and for evaluating the need for heart surgery.
4- Biochemical testing including complete blood picture with differential count, blood glucose level, thyroid profile and blood calcium level.
5- chromosomal analysis
6- Molecular cytogenetic study: FISH technique.
Results
25% of studied WS patients had short stature, 33.33% were underweight and 25% were microcephalic. Congenital cardiac abnormalities were present in 91.67% of patients. The most common heart anomaly was supravalvular aortic stenosis that was diagnosed in 75% of patients. The 2nd most common was peripheral pulmonary venous stenosis preset in 41.67%. Hypocalcemia was found in 16.67% whereas hypercalcemia occurred in 8.33%. Only 16.67% had hypothyroidism. Results of IQ testing of patients ranged from 40 to 78 with mean: 66.68. Fluorescent in situ hybridization was done in Eleven patients with clinical diagnoses of WS. Positive FISH deletion was observed in ten out of them (90.9 %)