DiGeorge syndrome is a rare congenital primary immune deficiency disease that includes symptoms such as abnormal characteristic facial features, increased susceptibility to infection, hypoplasia of thymus and parathyroid glands and cardiomyopathy. The incidence of DiGeorge syndrome is in the range of 1 per 3000 births, causing morbidity and mortality mainly due to congenital heart defect, where most deaths occur 6 months after birth. The second most common cause of mortality is infections due to severe immune deficiency. The syndrome is frequently progressive to psychomotor retardation with a 50% chance of mental retardation.
Most patients with DiGeorge syndrome have a micro deletion from chromosome 22 at position q11.2, produced by an error in recombination at meiosis. The symptoms of the disease are related to the amount of genetic material lost in the deletion.
Bastaki et al. (2000) carried out a case-control study on 20 subjects suffering from CATCH 22 syndromes (monosomy 22q11.2) and 40 controls at Adan Hospital in Kuwait. The study was performed to determine the spectrum of diseases, the clinical characteristics and several risk factors connected to this syndrome.FISH method was employed and demonstrated 20% maternal carrier, 10% paternal carrier, and 10% parental mosaicism with both parents being asymptomatic.(Bastaki L, Al-Awadi S, Abul-Hasan S, Abdul-Khalek E, Azab A, Gouda S, Naguib K. CATCH 22 in Kuwait: a study of 20 families. Alexandria J Pediatrics. 2000; 14(1):101-6.)
[See also: Saudi Arabia > Mathew et al., 1986].
Mansour et al. (2005) conducted a retrospective study of 240 consecutive patients with congenital heart disease.Of the 105 syndromic subjects, five were found to have DiGeorge syndrome.
Mathew et al. (1986) reported two children with hypoparathyroidism as part of DiGeorge Syndrome.
In 1999, Iqbal et al. used fluorescent in situ hybridization (FISH) to diagnose microdeletion syndromes in 4 patients with DiGeorge syndrome [del(22)(q11.2q11.23)]. They used the D22S75 DiGeorge chromosome region probe with chromosome 15 control probe.
Sztriha et al. (2004) reported two boys with chromosome 22q11 deletion syndrome and polymicrogyria. Both patients showed severe developmental delay with cardiovascular malformations and one of them had drug resistant epilepsy. Both patients showed monosomic microdeletion at 22q11.2 upon FISH analysis.