Al Talabani et al. (1998) studied the pattern of major congenital malformations in 24,233 consecutive live and stillbirth at Corniche hospital, which is the only maternity hospital in Abu Dhabi, between January 1992 and January 1995. A total of 401 babies (16.6/1,000), including 289 Arabs, were seen with major malformation. In their study, Al Talabani et al. (1998) observed 13 cases of cleft lip and palate in families from the United Arab Emirates. Recurrence was reported in four families.

Al Omari and Al-Omari (2004) conducted a retrospective investigation to determine the prevalence of oral clefts in Jordanian children born during the period 1991 to 2001. The overall prevalence rate for live births with cleft lip, cleft palate, or both was 1.39 per 1000 live births. Thirty percent of the clefts identified affected the lip, 22 percent affected the palate, and 48 percent involved the clefts of the lip and palate. In general, higher prevalence rates were found for boys than girls (55% boys versus 45% girls). There was a statistically significant sex difference between the cleft types. Clefts of the isolated palate, however, were more common in girls. Eighteen percent of patients with cleft were associated with major anomalies or syndromes.

Naguib (1989) described the syndromal and non-syndromal forms of cleft lip with or without cleft palate in Kuwait. Further details on this report could not be accessed.

[Naguib KK. Syndromal and nonsyndromal cleft lip with or without cleft palate in kuwait. Ann Saudi Med. 1989; 9(4):388-92.]

Srivastava and Bang (1990) retrospectively studied all new cases of facial clefts seen at a Kuwaiti hospital in a 2-year period (1985-1987). A total of 234 Arab children affected with facial clefts were seen in this period. These cases were compared to white Caucasian affected children seen in a hospital in England in this same period. Interestingly, the two groups showed the same pattern of clefting.

Al-Bustan et al. (2002) conducted a genetic epidemiological study to ascertain some epidemiological factors such as sex and consanguinity that may be associated with cleft lip with or without cleft palate (CL±CP) as well as to conduct genetic segregation analysis for contrasting Mendelian and non-Mendelian models of transmission in the families. This study was performed on 113 families ascertained through 121 CL±CP and CP surgical probands. The 121 patients surveyed included 66 males and 55 females from various nationalities with 62% Kuwaitis and 38% non-Kuwaitis of Arab and Asian origin who have been living in Kuwait for a long period. Of the 121 patients included in this study, 34 (28.1%) had CP, 30 (24.8%) had CL and 57 (47.1%) had CL+CP. The male to female ratio was found to be 0.89 for CP, 1.14 for CL, 1.35 for CL+CP and 1.2 for all the clefts. The percentage of consanguineous families among those with a positive family history (60%) was not significantly different from that of the general population (54.3%); whereas for all the families with clefts the percent consanguineous was significantly lower (38%). Based on these results, Al-Bustan et al. (2002) concluded that no definite association was observed between consanguinity and the occurrence of facial clefts in Kuwait. Also, Al-Bustan et al. (2002) performed genetic segregation analysis on 76 families with extended pedigrees and included only those with non-syndromic CL±CP (NS CL±CP). The results of the genetic segregation analysis were uninformative in that all models were equally likely and it was not possible to perform hypothesis testing. Additionally, they tested the heterogeneity by fitting general transmission models in the full data set (76 pedigrees), plus Arab (53 pedgrees) and Nomad (23 pedgrees). Al-Bustan et al. (2002) did not observe any evidence of heterogeneity in the results between the Arab and nomad subsets.

Rajab and Thomas (2001) determined the incidence of oral clefts (OC) in Oman by conducting a retrospective study based on hospital records of patients who underwent plastic surgery and information from maternity unit registers of babies born between the years 1989 to 1995. To study the seasonal variation, the date of conception was calculated from the date of birth and any association with the incidence of oral cleft (OC) was estimated by the method of Hewitt, while the student's t-distribution was used to estimate the relationship of parental age and birth order with OC. Consanguinity rates and the inbreeding coefficient of OC patients were calculated and compared with that of the general population. According to the plastic surgery records during the period of 1989 and 1995, 563 children were found to have been born with OC (overall incidence -1.5 per 1000 live births; 0.34 per 1000 live births for isolated cleft lip, 0.62 per 1000 live births for combined lip and palate cleft). The prevalence of OC according to the maternity units' records was 1.0 per 1000 for cleft lip and combined lip and palate cleft cases. The incidence, prevalence and sex ratio of cleft palate could not be estimated as the diagnosis was often missed in the delivery records. A statistically insignificant seasonal variation was noted in this study, as most of the children with OC were born during the six-month period of high temperatures (June to November), which meant that their conception was in the cold months of the year (September to January). A study on 177 patients seen in the plastic surgery clinic in the year 1995 revealed significantly higher rate of first-degree cousin consanguinity (45%) among parents of OC children when compared to the general population (25%), and an inbreeding coefficient of 0.0294 (compared to 0.0198 in general population). In 58.4% of the cases studied, associated anomalies were detected with congenital malformation syndromes (17 children had congenital heart disease). In 23% of children with OC, there was a positive family history of OC, and 10% had siblings with a history of congenital heart disease and mental retardation. On analyzing the parental age and birth order, it was found that younger children were more likely to be affected with OC and that their mean parental ages were significantly higher than in the general population. It was also found that mothers of three patients had history of amniotic fluid leakage during pregnancy, one had gestational diabetes, one had clomphine citrate-induced pregnancy, and two mothers were taking anticonvulsant drugs during pregnancy. Rajab and Thomas (2001) recommended the referral of such children to genetic clinics for thorough investigation, as there was high prevalence of familial cases, congenital defects and congenital malformation syndromes, and advised on further prospective studies on the influence of local dietary, environmental and genetic factors on the occurrence rate of OC in Oman.

[Rajab A, Thomas C. Oral clefts in the Sultanate of Oman. Eur J Plast Surg. 2001; 24:230-3.]

Sawardekar (2005) conducted a study to establish the prevalence of major congenital malformations in children born during a 10-year period in an Omani hospital in Nizwa. Of the 21,988 total births in the hospital, 53 children were born with cleft lip and/or palate. Sawardekar (2005) hinted for a possible genetic contribution in these children.

The cleft lip and/or palate phenotype was the subject of a study conducted by Aljohar et al. (2007), who looked retrospectively at 807 cases of cleft lip and/or palate in Saudi Arabia. The cases were registered at King Faisal Specialist Hospital and Research Center in Riyadh from June 1999 to December 2005. The sample consisted of 451 boys and 356 girls. The cases were sub-classified phenotypically to 387 cases of cleft lip and palate, 294 cases of isolated cleft palate, and 122 of isolated cleft lip. Girls predominated in isolated cleft palate while boys predominated the other two subclasses. In 439 cases, parents were consanguineous, while a family history for such clefts was seen in 224 cases. Two hundred and thirty eight cases had associated anomalies, 91 of them were congenital heart disease. Interestingly, 23% of the 122 children with isolated cleft lip, 40% of the 294 children with isolated cleft palate, and 23% of the 387 children with cleft lip and palate had associated malformations. This study uncovered no major differences in the pattern of cleft reported from other Arab countries.

Wyszynski et al. (2003) identified gene loci for non-syndromic cleft lip with/without cleft palate (CL/P). Two large, relatively isolated Syrian families were involved in the study and a gene-wide linkage analysis was performed. One of the two families had 18 cases and the other had four cases with CL/P. Some of the parents in these two families were consanguineous. A locus on 17p13.1 was detected with a multipoint LOD (logarithm of the odds) score of 2.8 and a 2-point-non-parametric MLS (maximum LOD score) of 3.0. Also, other loci were determined with multipoint LOD scores =1.2 (P= 0.01) and they included 3p21.2, 4q32.1, and 7q34. Wyszynski et al. (2003) concluded that CL/P has several susceptibility loci, and the strongest candidate locus in their study was 17p13. One year later, Marazita et al. (2004) revealed that complete sequencing of the MSX1 (msh homeobox homolog 1) gene showed mutations in about 2% of CL/P cases in the Wyszynski et al. (2003) study.

Hosani and Czeizel (2000) evaluated the pilot dataset [March-May 1998] of the UAE National Congenital Abnormality Registry (NCAR). A total of 4,861 births were recorded in this study period, with a birth prevalence of total congenital anomalies being 30.3/1,000 births. Cleft lip with or without cleft palate was identified in four neonates, resulting in an incidence rate of 0.82/1,000 births.