Estimating the birth prevalence and pregnancy outcomes of congenital malformations worldwide

Congenital anomaly registries have two main surveillance aims: firstly to define baseline epidemiology of important congenital anomalies to facilitate programme, policy and resource planning, and secondly to identify clusters of cases and any other epidemiological changes that could give early warning of environmental or infectious hazards. However, setting up a sustainable registry and surveillance system is resource-intensive requiring national infrastructure for recording all cases and diagnostic facilities to identify those malformations that that are not externally visible. Consequently, not all countries have yet established robust surveillance systems. For these countries, methods are needed to generate estimates of prevalence of these disorders which can act as a starting point for assessing disease burden and service implications. Here, we describe how registry data from high-income settings can be used for generating reference rates that can be used as provisional estimates for countries with little or no observational data on non-syndromic congenital malformations.

Experience of a multidisciplinary task force with exome sequencing for Mendelian disorders

BACKGROUND

In order to optimally integrate the use of high-throughput sequencing (HTS) as a tool in clinical diagnostics of likely monogenic disorders, we have created a multidisciplinary "Genome Clinic Task Force" at the University Hospitals of Geneva, which is composed of clinical and molecular geneticists, bioinformaticians, technicians, bioethicists, and a coordinator.

METHODS AND RESULTS

We have implemented whole exome sequencing (WES) with subsequent targeted bioinformatics analysis of gene lists for specific disorders. Clinical cases of heterogeneous Mendelian disorders that could potentially benefit from HTS are presented and discussed during the sessions of the task force. Debate concerning the interpretation of identified variants and the content of the final report constitutes a major part of the task force's work. Furthermore, issues related to bioethics, genetic counseling, quality control, and reimbursement are also addressed.

CONCLUSIONS

This multidisciplinary task force has enabled us to create a platform for regular exchanges between all involved experts in order to deal with the multiple complex issues related to HTS in clinical practice and to continuously improve the diagnostic use of HTS. In addition, this task force was instrumental to formally approve the reimbursement of HTS for molecular diagnosis of Mendelian disorders in Switzerland.

Sanjad Sakati syndrome: a case series from Jordan

Sanjad Sakati syndrome is a rare autosomal recessive disorder that has been described in Arabs. We report 8 patients from 7 Jordanian families, 6 of whom underwent genetic testing and were found to have a 12 bp (155-166 del) deletion within the tubulin-specific chaperone E (TBCE gene) in exon 3 at 1q42-43. All patients had severe growth retardation, distinct phenotypic features and hypoparathyroidism. Parental consanguinity was recorded in all families. This is the first genetically proven case series of Sanjad Sakati syndrome in Jordan.

Genetic clinics in arab communities: meeting individual, family and community needs

Arab societies are characterized by a wide range of family and social structures, religious and legal conventions, and highly variable economic resources. As might be expected under these circumstances, genetic services cannot readily be devised, delivered, and assessed according to a single model. However, in general terms, the provision of genetic services in Arab communities at all population levels is still inadequate given the prevalence and burden of genetic diseases. Improving this situation calls for major educational efforts that include increasing the genetic literacy of the general public, comprehensive courses and campaigns to familiarize primary health care workers with counseling needs and skills and with referral guidelines for high-risk families, updating medical, nursing, and paramedical curricula to incorporate information on community genetics, and training clinical and laboratory genetic specialists to meet the short- and long-term goals of genetic disease prevention and management.

Congenital pseudoarthrosis associated with venous malformation

Congenital pseudoarthrosis is a pathologic entity that may be isolated, or may be associated with neurofibromatosis. We report the case of a 3-year-old female with congenital pseudoarthrosis involving the right tibia and fibula. Magnetic resonance imaging (MRI) and complementary magnetic resonance angiogram (MRA) revealed a lobulated mass with vivid enhancement, which led to the diagnosis of venous malformation. This is the first report of congenital pseudoarthrosis caused by the presence of a vascular malformation.

Consanguineous marriages in Jordan: why is the rate changing with time?

The objective of this study was to explore the secular trend in consanguinity in Jordan and the subtypes of consanguineous marriages that may be undergoing a change. A total of 1032 individuals attending a diabetic clinic in Amman were interviewed. The questionnaire provided information on consanguinity status and date of marriage among three generations: the persons interviewed, their parents, parents of their spouses and their offspring. Data on consanguinity status among 5401 marriages was obtained. Generations were named generation 1 for marriages contracted before 1950, generation 2 for marriages contracted between 1950 and 1979, and generation 3 for marriages contracted after 1980. For generations 1, 2, and 3, first-cousin marriages constituted 20.2, 28.5 and 19.5% of all marriages, respectively, while the subtype of paternal parallel first-cousin marriages constituted 75.6, 60.3 and 43.3% of all first-cousin marriages, respectively. The offspring of first-cousin parents were significantly more prone to marry their relatives than the offspring of non-consanguineous parents, with rates of first-cousin marriages among offspring of first-cousin parents and non-related parents constituting 25.3 and 17.1% of all marriages, respectively. For generations 1, 2 and 3, the average coefficient of inbreeding was 0.0135, 0.02 and 0.0142, respectively. In conclusion, first-cousin marriage rate among a representative population from Amman showed a significant decline among marriages contracted after 1980 compared to marriages contracted between 1950 and 1979, but not to marriages contracted before 1950. The proportion of paternal parallel first cousins among first-cousin marriages showed a steady decline from one generation to the next.

Hereditary disorders in the Eastern Mediterranean Region

Hereditary diseases and congenital malformations have been reported to affect 2-5% of all live births. Available evidence suggests that genetic disorders are equally important also in countries of the Eastern Mediterranean Region. Considerable achievements have been made over the last two decades in controlling communicable diseases in the region. Concurrently, there has been a mounting awareness of the increasing importance of hereditary disorders. Certain genetically determined diseases such as the haemoglobinopathies and enzymopathies are extremely common in the region and the need to initiate public health measures for their control is increasingly being recognized. The following factors may contribute to the elevated prevalence of genetically determined disorders: the high consanguinity rates; the high frequency of haemoglobinopathies and glucose-6-phosphate dehydrogenase deficiency; the trend of continuing to bear children up to menopause; the general lack of public awareness about genetic diseases; and the dearth of genetic services in the region. These and some other related issues are discussed in detail in this review article.

Sister chromatid exchange frequencies in a group of individuals with unfavorable reproductive health

Sister chromatid exchange (SCE) frequencies and other cytogenetic parameters were investigated in peripheral blood lymphocytes from 92 subjects comprising 44 parents of malformed offspring or repeated fetal wastage (Group I) and 48 controls, age and sex matched, having normal reproductive health (Group II). The karyotypes were normal and the mean mitotic indices were comparable in both groups. The mean frequency of SCE per metaphase in Group I (8.67 +/- 0.32) was significantly higher than the mean for group II (6.65 +/- 0.16), and the cellular replicative index in Group I (1.78 +/- 0.04) was significantly different from that of Group II (1.66 +/- 0.03). The results are discussed in the light of the present understanding of the etiology and mechanism of production of sister chromatid exchanges.