Hu et al. (1992) analyzed the CA2 gene in six unrelated Arab patients suffering from CA2 Deficiency. Five of these were found to be homozygous for a novel splice junction mutation at the 5' end of intron 2. The sixth patient was heterozygous for this mutation. Hu et al. (1992) named this as the 'Arabic' mutation.

Samilchuk et al. (1996a) reported the detection of the splice junction mutation in intron 2 of the CA2 gene in a Kuwaiti patient with Osteopetrosis with Renal Tubular Acidosis and Cerebral Calcification (ORTACC). Furthermore, Samilchuk et al. (1996b) reported the mutation in two Kuwaiti brothers who came of a consanguineous family and both were homozygous for the over-mentioned mutation. This result warrants implementing relevant tests to detect this mutation in Kuwaiti families with ORTACC. [Samilchuk E, D'Souza B, Al-Awadi S. Molecular diagnostics and carrier identification for metabolic diseases in Kuwait. Proceedings of the 10th Scientific Congress of the Kuwait Medical Association. 1996b; 164-5.]

Lotan et al. (2006) studied affected members of a family with the CA2 deficiency syndrome and having the "Egyptian mutation" in CA2 c.191delA (p.H64fsX90). One affected member, homozygote for the mutation, developed primary pulmonary hypertension. Lotan et al. (2006) added that primary pulmonary hypertension was never described before in patients with this unique syndrome and they speculated that there might be a possible etiologic link between these entities.

Fathallah et al. (1994) screened 10 Tunisian patients with CA2 Deficiency for the splice junction 'Arabic' mutation at the 5'end of the CA2 gene. All 10 patients were found to be homozygous for this mutation. All patients were also mentally retarded. Fathallah et al. (1994) suggested that this mutation may be confined to this ethnic group. Later on, Fathallah et al. (1997) conducted a filiation study to trace these families back to a common Arabic tribe that settled in the Maghreb (North Africa) in the 10th century. By sequence-tagged site analysis, Fathallah et al. (1997) showed cosegregation of the Taq (-) allele with the mutation in 12 families out of 14. This observation supported a founder effect to explain the common CAII deficiency allele in the Tunisian population. In the remaining two families, a genomic recombination or gene conversion occurred between the TaqI restriction marker and the mutation causing the disease. Fathallah et al. (1997) suggested the presence of a hot spot for recombination or gene conversion at the CA II locus because of the relatively high recombination frequency observed.