Oil phytoremediation potential of hypersaline coasts of the Arabian Gulf using rhizosphere technology.

The rhizosphere and phyllosphere of the halophyte Halonemum strobilaceum naturally inhabiting hypersaline coastal areas of the Arabian Gulf harbor up to 8.1 x 10(4)g(-1) and 3 x 10(2)g(-1), respectively, of extremely halophilic oil-utilizing microorganisms. Such organisms were 14- to 38-fold more frequent in the rhizosphere than in the plant-free soil. Frequent genera in the rhizosphere were affiliated to the archaea Halobacterium sp. and Halococcus sp., the firmicute Brevibacillus borstenlensis, and the proteobacteria Pseudoalteromonas ruthenica and Halomonas sinaensis. The phyllospheric microflora consisted of the dimorphic yeast Candida utilis and the two proteobacteria Ochrobactrum sp. and Desulfovibrio sp. Individual strains grew on a range of pure aliphatic and aromatic hydrocarbons, as sole sources of carbon and energy. All the strains, except C. utilis which could not tolerate salinities >2M NaCl, grew also in media with salinities ranging between 1 and 4M NaCl, with optimum growth between 1 and 2M NaCl. With the exception of the two archaeal genera, all isolates could grow in a nitrogen-free medium. The total rhizospheric and phyllospheric microbial consortia could attenuate crude oil in complete (nitrogen-containing) medium, but also equally well in a nitrogen-free medium. It was concluded that H. strobilaceum could be a valuable halophyte for phytoremediation of oil-polluted hypersaline environments via rhizosphere technology.

Are medullary breast cancers an indication for BRCA1 mutation screening? A mutation analysis of 42 cases of medullary breast cancer.

Recommended guidelines have limited breast cancer gene ( BRCA1 ) mutation testing to individuals with a personal or family history of early onset breast and/or ovarian cancer, and those with multiple affected close relatives. Such large breast cancer families are rare in the general population, limiting the clinical application of the BRCA1 discovery. Previous reports have suggested an association between medullary breast cancer and BRCA1 mutation carriers. To test the feasibility of using these rare histological subtypes as an alternative to epidemiological factors, 42 cases of medullary cancer unselected for family history were screened for BRCA1 point mutations and large exon rearrangements. The large majority (83%) of these patients did not have significant family of breast or ovarian cancer. Two deleterious mutations resulting in a premature stop codon, and one exon 13 duplication were found. All mutations were detected in patients with typical medullary cancer, who had family history of multiple breast and ovarian cancers. Our findings suggest that medullary breast cancers are not an indication for BRCA1 mutation screening in the absence of significant family risk factors.

Loss of heterozygosity in bilateral breast cancer.

Women who develop bilateral breast cancer at an early age are likely to harbour germline mutations in breast cancer susceptibility genes. The aim of this study was to test for concordant genetic changes in left and right breast cancer of young women (age < 50) with bilateral breast cancer that may suggest an inherited breast cancer predisposition. Microsatellite markers were used to test for loss of heterozygosity (LOH) in left and right tumours for 31 women with premenopausal bilateral breast cancer. Markers adjacent to or within candidate genes on 17p (p53), 17q (BRCA1), 13q (BRCA2), 11q (Ataxia Telangiectasia-ATM) and 3p (FHIT) were chosen. Mutational testing for BRCA1 and BRCA2 was performed for cases where blood was available. Concordant LOH in both left and right tumours was demonstrated for at least one of the markers tested in 16/31(54%) cases. Where allelic loss was demonstrated for both left and right breast cancer, the same allele was lost on each occasion. This may suggest a common mutational event. Four cases showed concordant loss of alleles in both left and right breast cancer at D17S791 (BRCA1). BRCA1 mutations were identified in two of these cases where blood was available. Four cases showed concordant LOH at D13S155 (BRCA2). Concordant LOH was further demonstrated in seven cases for D11S1778 (ATM) and four cases for D3S1300 (which maps to the FHIT gene), suggesting a possible role for these tumour suppressor genes in this subgroup of breast cancer patients. No concordant allelic loss was demonstrated for D17S786 suggesting that germline mutations in p53 are unlikely in such cases of bilateral breast cancer.

Greig cephalopolysyndactyly syndrome with dysgenesis of the corpus callosum in a Bedouin family.

We report on the first known Bedouin family with Greig cephalopolysyndactyly syndrome (MIM 175700). The index patient and his father shared pre- and postaxial polysyndactyly, mild mental retardation, and corpus callosum dysgenesis. Their phenotypic findings were compared with reported cases of both Greig cephalopolysyndactyly (GCPS) and acrocallosal syndromes. This family represents the second report of the rare occurrence of dysgenesis of the corpus callosum in GCPS.

Disease profile of 400 institutionalized mentally retarded patients in Kuwait.

In this preliminary report we summarize the results of a 4-year multidisciplinary systematic, etiological clinicogenetic survey of 400 institutionalized mentally retarded patients in Kuwait. All had an intelligence quotient below 50. A constitutional disorder, as the direct cause of the mental retardation, was found in 203 patients (50.75%)): a chromosomal abnormality in 37 (9.25%), Mendelian disorders in 137 (34.25%), MCA/MR in 22 (5.55%) and CNS malformations in 7 cases (1.75%). In 157 patients (39.35%) a pre-, peri or postnatal cause was ascertained. No etiological diagnosis was detected in 40 patients (10%). A detailed analysis of the "disease profile" is given and compared with the results of previous diagnostic genetic surveys among different institutionalized mentally retarded populations in Western and developing countries.

The newly recognised limb/pelvis-hypoplasia/aplasia syndrome: report of a Bedouin patient and review.

A Bedouin infant born to consanguineous parents and grandparents is reported. She had Müllerian aplasia and the phenotypic features of the limb/pelvis-hypoplasia/aplasia syndrome (MIM 276820). Phenotypic variability of this newly recognised syndrome is briefly discussed.

Osteoporosis-pseudoglioma syndrome with congenital heart disease: a new association.

We report a sibship of two brothers and one sister with the osteoporosis-pseudoglioma syndrome and congenital heart disease. They presented in infancy with visual impairment and psychomotor retardation. Major features included bilateral cataracts, generalised osteopenia, severe platyspondyly, borderline mental retardation, muscular hypotonia, joint laxity, and ventricular septal defect. Parental consanguinity and affected sibs of both sexes strongly suggested autosomal recessive inheritance. Analysis of the present and previously reported cases showed a wide range of interfamilial variability which may point to the existence of multiple allelism or genetic heterogeneity in this syndrome.

Trisomy 18 clustering in Kuwait.

Thirteen cases of trisomy 18 (T18) were ascertained clinically and cytogenetically during the period 1984-1986. Eight cases were delivered during 1986 in the Maternity Hospital out of 17,318 live births, making an incidence of 4.61/10,000, which is significantly higher than the international incidence as well as the incidence in previous years. The female-to-male sex ratio was 1.8/1, the median maternal age 32.5, and the median paternal age 40. There was no history of polyhydramnios. Five cases were delivered by cesarean section and four cases died in the neonatal period. All cases proved to be full trisomy 18 with no mosaicism detected; in one case parental inversion 9 was detected.

Brachmann-de Lange syndrome in sibs.

We report an Arab family of phenotypically normal first cousin parents with two offspring showing variable manifestations of Brachmann-de Lange syndrome. The proband, who had many diagnostic symptoms of the syndrome with apparently normal chromosomes, died at the age of three months. His sister was less severely affected and lived for six years. The genetic basis of Brachmann-de Lange syndrome is discussed and homozygosity for an autosomal recessive allelle is suggested as an underlying cause in some cases.