Search

A pilot project was undertaken for implementing genetic counseling in the Arab Community by choosing at random, a Muslim village of 8600 inhabitants as the site for the project. The data collected during the oral interviews demonstrated that the tradition of marrying a relative remains central, although some changes in marriage preference have occurred.

Background: Several meta-analyses assessed the relationship between exposure to PM with aerodynamic diameter ≤ 2.5 μm (PM 2.5 ) during pregnancy and birth weight (BW), but results were inconsistent and substantial unexplained heterogeneity was reported. We aimed to investigate the above association and to explore sources of heterogeneity across studies., Methods: We systematically reviewed the current worldwide evidence examining the association between PM 2.5 and BW. The review protocol was registered on the PROSPERO website (CRD42020188996) and followed PRISMA guidelines. We extracted association measures for BW and low birth weight (LBW, BW < 2500 g) from each study to evaluate pooled summary measures and to explore sources of between-study heterogeneity., Findings: Of the 2677 articles identified, 84 met the inclusion criteria (~42 M births). Our random effects meta-analyses revealed substantial heterogeneity among included studies (I 2  = 98.4 % and I 2  = 77.7 %, for BW and LBW respectively). For LBW, the heterogeneity decreased (I 2  = 59.7 %) after excluding four outlying studies, with a pooled odds ratio 1.07 (95 % confidence interval, CI: 1.05, 1.09) per a 10-μg/m 3 increase in mean PM 2.5 exposure over the entire pregnancy. Further subgroup analysis revealed geographic heterogeneity with higher association in Europe (1.34, (1.16, 1.55)) compared to Asia (1.06, (1.03, 1.10)) and US (1.07, (1.04, 1.10))., Conclusion: The association between PM 2.5 and birth weight varied depending on several factors. The sources of heterogeneity between studies included modifiers such as study region and period. Hence, it is advisable not to pool summary measures of PM 2.5 -BW associations and that policy would be informed by local evidence., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The three homeotic genes of the bithorax complex (BX-C), Ubx, abd-A and Abd-B control the identity of the posterior thorax and all abdominal segments. Large segment-specific cis-regulatory regions control the expression of Ubx, abd-A or Abd-B in each of the segments. These segment-specific cis-regulatory regions span the whole 300 kb of the BX-C and are arranged on the chromosome in the same order as the segments they specify. Experiments with lacZ reporter constructs revealed the existence of several types of regulatory elements in each of the cis-regulatory regions. These include initiation elements, maintenance elements, cell type- or tissue-specific enhancers, chromatin insulators and the promoter targeting sequence. In this paper, we extend the analysis of regulatory elements within the BX-C by describing a series of internal deficiencies that affect the Abd-B regulatory region. Many of the elements uncovered by these deficiencies are further verified in transgenic reporter assays. Our results highlight four key features of the iab-5, iab-6 and iab-7 cis-regulatory region of Abd-B. First, the whole Abd-B region is modular by nature and can be divided into discrete functional domains. Second, each domain seems to control specifically the level of Abd-B expression in only one parasegment. Third, each domain is itself modular and made up of a similar set of definable regulatory elements. And finally, the activity of each domain is absolutely dependent on the presence of an initiator element.

Genetic disorders are frequent in the Arab population of Israel, mainly because of the preference for consanguineous marriages. Many of the inherited diseases are present with a high frequency only in a limited region or a single village. It is therefore not surprising that, in each of the villages, a different distribution of genetic diseases is found; thus, a detailed knowledge of the genetic disorders present in each village is of utmost importance for genetic counseling. As a direct consequence of these observations two community genetics clinics were opened as a pilot project to study their impact on the population to be served. The use of a computer database allowed for easier and more accurate genetic counseling. There were almost 1,500 visits in the 4-year period since the introduction of the services. During the years an increase in the mean number of consultations per clinic as well as a change in the type of referrals was observed. There was an increasing proportion of clinics that were made at a time in which genetic counseling allow for primary prevention. The presence of a genetic counselor in the village clinic allows for better and closer contacts with the family physician., (Copyright 2006 Wiley-Liss, Inc.)

In a small village founded by few ancestors, three mutations in GJB2, the gene for connexin 26, are responsible for the high prevalence of deafness. A total of 15% of healthy individuals from a random sample were carriers of either 35Gdel (7.8%), W77R (2.4%), or V37I (4.8%). The three mutations appeared in the village approximately 100-150 years ago. The question of why three distinct mutations of similar age are observed at high frequency within a genetic isolate is discussed.

In Israel, as in several countries of the Mediterranean basin, beta-thalassemia is frequent among Arabs, and many different mutations in the beta globin gene have been identified. In a single Arab village, three different thalassemia mutations, as well as the sickle-cell mutation, were characterized. Using genealogical data as well as the results of screening in the village population, we were able to demonstrate/speculate on how mutations were introduced into the village and how they later expanded. The sickle-cell mutation became particularly prevalent in the village as the result of a founder effect due to a preference for consanguineous marriages., (Copyright 2005 Wiley-Liss, Inc)

In a Muslim Israeli Arab village, different types of hearing loss affect some 2% of the inhabitants. Most cases of profound deafness are due to recessive mutations in the Connexin-26 gene. Since in this community, marriages are by preference within the family (consanguineous), for many of the couples from the village the risk for an affected child is high. There are 30 families living in the village in which both parents have normal hearing and at least one child has a profound hearing defect. In these families, the birth of a child with profound deafness did not change family planning. The rate of marriage was similar for the siblings of deaf children as for other individuals in the village. The major problems were encountered by the deaf individuals themselves; in particular, most of the women were not married. Because of the distinctive nature of this particular problem, different types of screening programs were envisaged. However, all of them are problematic. Therefore, as a first step it was decided to begin a program including individual genetic counseling together with education of the entire population on practical aspects of human genetics.

Chromatin domain boundaries, like scs or gypsy insulators in Drosophila, have been identified in transgene assays through their enhancer-blocking activity. Boundary elements in the bithorax complex (BX-C), such as Fab-7 and Fab-8, have been identified genetically and been shown to have insulator activity in transgene assays. However, it is not clear whether boundary elements identified in transgene assays will function appropriately in chromosomal contexts such as BX-C. Using gene conversion, we have substituted the scs or gypsy insulators for Fab-7. We find that both scs and gypsy are very potent insulators in the ectoderm, but surprisingly, the insulating activity of gypsy (but not scs) is lost in the CNS. Our results reveal that the Fab-7 boundary must have special properties that scs and gypsy lack, which allow it to function appropriately in BX-C regulation.

In the work reported here we have undertaken a functional dissection of a Polycomb response element (PRE) from the iab-7 cis-regulatory domain of the Drosophila melanogaster bithorax complex (BX-C). Previous studies mapped the iab-7 PRE to an 860-bp fragment located just distal to the Fab-7 boundary. Located within this fragment is an approximately 230-bp chromatin-specific nuclease-hypersensitive region called HS3. We have shown that HS3 is capable of functioning as a Polycomb-dependent silencer in vivo, inducing pairing-dependent silencing of a mini-white reporter. The HS3 sequence contains consensus binding sites for the GAGA factor, a protein implicated in the formation of nucleosome-free regions of chromatin, and Pleiohomeotic (Pho), a Polycomb group protein that is related to the mammalian transcription factor YY1. We show that GAGA and Pho interact with these sequences in vitro and that the consensus binding sites for the two proteins are critical for the silencing activity of the iab-7 PRE in vivo.

A complementary deoxyribonucleic acid (cDNA) clone encoding an alpha thyroid hormone receptor (TR alpha) from muscovy duckling liver was isolated and sequenced. Comparison with the chicken TR alpha sequence showed a high degree of homology. Despite 45 nucleotide substitutions, the deduced peptide sequence was similar. This cDNA was used as a probe to characterize the TR alpha mRNA transcripts expressed in muscovy duckling liver and skeletal muscle.

A cDNA clone encoding a beta-thyroid hormone receptor (TRbeta) from muscovy duckling liver was isolated and sequenced. Comparison with the chicken TRbeta sequence showed a high degree of homology. This cDNA was used as a probe to characterize the TRbeta mRNA transcripts expressed in muscovy duckling liver.