Cystic Fibrosis in Gaza Strip: Mutation Analysis and Major Disease Manifestations

Cystic fibrosis (CF) is a devastating autosomal recessive disorder caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene the product of which is responsible for the transport of chloride ions across the membranes of epithelial cells. The disease is characterized by abnormally high sweat electrolytes, exocrine pancreatic insufficiency and chronic pulmonary obstruction, causing progressive disability and ultimately death. The aim of the present work was to determine for the first time in Gaza strip the common CF mutations and the major disease manifestations in Palestinian CF patients. The study population consisted of one hundred CF cases, 71% of them were males. The average age of the subjects was 70.6±44 months. Ninety three percent of the cases had white colored skin. Most of the CF cases (85%) were initially diagnosed by clinical manifestations and sweat test. The most frequent respiratory manifestations among CF cases were recurrent chest infections and chronic cough with viscid sputum whereas, the most frequent gastrointestinal manifestations were recurrent gastroenteritis, abdominal colic and flatulence, and malabsorption. Regarding the anthropometric measurements most CF cases had short stature (86%), 94% were underweight, and 65% had wasting. Also, 82% of CF cases were anemic. Allele-specific PCR was employed for screening DNA samples available from 64 patients for nine mutations: ΔF508, 3120+1G>A, N1303K, G85E, 1717+1G>A, G542X, W1282X, and 1209G>A, whereas, mutation 3120+1kbdel8.6kb was assayed by multiplex PCR. The results of mutation testing revealed that 61% of mutation-identified CF cases have at least a single ∆F508 allele. Moreover, 12.2% were homozygous for the 3120+1G>A CFTR mutation. Homozygous N1303K, G85E and 3120+1kbdel8.6kb mutations occurred in equal proportions and collectively represented 14.7%. The recorded CFTR homozygous mutations could be classified as: 51.2% class II, 19.5% class V, 4.9% class I and 2.4% class IV. The study shows that CF is not uncommon in Gaza strip and the findings will be useful for planning future screening and proper genetic counseling programs for Palestinian CF patients.