摘要:

Roberts syndrome is a rare autosomal recessive disorder with highly variable clinical features. The most notable manifestations include pre- and postnatal growth retardation, craniofacial anomalies and improper development of all four extremities. We reviewed 50 cases whose clinical evaluation has been vigorously pursued. A relationship of deformities exists between humerus versus femur, and radius and ulna versus tibia and fibula. Only six cases had clubfoot. The number of fingers and toes was variable. The sex ratio was 1:1. Most individuals died in early infancy, although the longest follow-up survival was 13 years in one case. Premature centromere separation, centromere splitting and puffing were common chromosomal abnormalities. An annotated bibliography on notable cases is also provided which should serve as an aid for clinicians who wish to further understand the genetic and clinical heterogeneity noted in their cases.

ISSN:0001-5652    

DOI:10.1159/000154204

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

We describe a parallel implementation of a genetic-linkage analysis program that achieves good speed improvement, even for analyses on a single pedigree and with a single starting recombination fraction vector. Our parallel implementation has been run on three different platforms: an Ethernet network of workstations, a higher-bandwidth asynchronous transfer mode (ATM) network of workstations, and a shared-memory multiprocessor. The same program, written in a shared-memory programming style, is used on all platforms. On the workstation networks, the hardware does not provide shared memory, so the program executes on a distributed shared memory system that implements shared memory in software. These three platforms represent different points on the price/performance scale. Ethernet networks are cheap and omnipresent, ATM networks are an emerging technology that offers higher bandwidth, and shared-memory multiprocessors offer the best performance because communication is implemented entirely by hardware. On 8 processors and for the longer runs, we achieve speedups between 3.5 and 5 on the Ethernet network and between 4.8 and 6 on the ATM network. On the shared-memory multiprocessor, we achieve speedups in the 5.5-6.5 range for all runs.

ISSN:0001-5652    

DOI:10.1159/000154205

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

We have determined the β-globin cluster haplotypes for 80 Indians from four Brazilian Amazon tribes: Kayapó, Wayampí, Wayana-Apalaí, and Arára. The results are analyzed together with 20 Yanomámi previously studied. From 2 to 4 different haplotypes were identified for each tribe, and 7 of the possible 32 haplotypes were found in a sample of 172 chromosomes for which the β haplotypes were directly determined or derived from family studies. The haplotype distribution does not differ significantly among the five populations. The two most common haplotypes in all tribes were haplotypes 2 and 6, with average frequencies of 0.843 and 0.122, respectively. The genetic affinities between Brazilian Indians and other human populations were evaluated by estimates of genetic distance based on haplotype data. The lowest values were observed in relation to Asians, especially Chinese, Polynesians, and Micron

ISSN:0001-5652    

DOI:10.1159/000154206

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

The HLA-DQα genotype and allele frequencies in 130 Malays, 125 Chinese, and 137 Indians in the Malaysian population were determined using a commercial HLA-DQα DNA amplification and typing kit which distinguishes 6 alleles (DQA1.1, DQA1.2, DQA1.3, DQA2, DQA3, and DQA4) and 21 possible genotypes at this locus. All 21 genotypes were encountered in the Malay and Indian samples, but DQA1.1, DQA1.3 and DQA2, DQA2 genotypes were absent in the Chinese sample. In all three ethnic groups, the numbers observed for the various DQα genotypes were in accordance with those expected from Hardy-Weinberg equilibrium. The allele frequencies observed in these three groups were significantly different to allow them to be distinguished as distinct populations. For the Malays, Chinese, and Indians, heterozygosity values at this locus were 0.77, 0.77, and 0.83, respectively, and values of the power of discrimination were 0.91, 0.90, and 0.94, respectively. These population data will enable the HLA-DQα locus to be used as a marker in forensic identity testing in Malay

ISSN:0001-5652    

DOI:10.1159/000154207

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

The genetic polymorphism of eight red cell enzymes was analyzed in population samples from the Northwest African Continent and from the South of Spain in order to study their genetic relationships with the Canarian population. The Moroccan, Berber and Spanish populations, although geographically more distant from the Canary Islands than the Saharan and Mauritanian ones, are genetically more closely related to the Canarian population. The glucose-6-phosphate dehydrogenase Gc allele earlier found only in the Canary Islands was detected in the Berber sample. The Spanish, Berber and African Black contributions to the Canarian hybrid population was estimated to 70, 20 and 10%, respectively.

ISSN:0001-5652    

DOI:10.1159/000154208

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

Asymmetry of a–b ridge count, a dermatoglyphic trait in the second interdigital (ID II) palmar area was studied in 314 identical (MZ) twin-pairs of known placental type. Statistically significant differences were observed for the variability of a-b ridge count with respect to placentation. Monochorionic MZ pairs displayed more within-pair variability than dichorionic MZ twins. Within dichorionic pairs, greater variability was observed in MZ twins when pairs with fused placentas were compared with those with separate placentas. A similar pattern of greater variability in dichorionic fused versus dichorionic separate placentas was also found in 121 same sex dizygotic twin-pairs. The pattern of within-pair differences was consistent with a placental proximity effect like that known for the variability in birth weight in twin

ISSN:0001-5652    

DOI:10.1159/000154209

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

The frequency of carriers of the ΔF508 mutation at the cystic fibrosis (CF) locus was studied in population samples of Finns, Lithuanians, Saamis (Lapps) and Swedes from northern Sweden. The carrier frequencies in northern Sweden (1:200) and in Lithuanians (1:143) were significantly lower than in southern Scandinavia (Denmark; 1:38). No ΔF508 carriers were found in Finns (n = 171) and Saamis (n = 151). The results indicate that the frequency of ΔF508 is low in Finno-Ugrian and Baltic populations, and the decreased frequency of ΔF508 in northern Sweden may be due to Finnish and Saamish admixt

ISSN:0001-5652    

DOI:10.1159/000154210

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

The δ-aminolevulinate dehydratase (ALADH) polymorphism was studied in the Upper Silesian population, Poland. The frequency of ALADH*1 was 0.9417, and ALADH*2 was 0.0583. No rare or anomalous phenotype was found. The distribution of phenotypes in 148 mother-child pairs was determined. Comparison with other world populations was made

ISSN:0001-5652    

DOI:10.1159/000154211

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

Restriction fragment length polymorphisms have previously been found in the placental alkaline phosphatase (PLAP) and germ cell alkaline phosphatase (GCAP) genes, but not in the closely related intestinal alkaline phosphatase (LAP) locus. We here report on a Pstlrestriction fragment length polymorphism in IAP found in Finns and Swedes but not in Saamis. A probable T→G mutation in position 175 of intron 11 would create a new cleavage site for PstI. The borderline frequency of the mutant allele (0.01) is in agreement with previous observations suggesting that IAP is considerably less polymorphic than PLAP and GCA

ISSN:0001-5652    

DOI:10.1159/000154212

出版商:S. Karger AG    

年代:1994

数据来源: Karger

ISSN:0001-5652    

DOI:10.1159/000154213

出版商:S. Karger AG    

年代:1994

数据来源: Karger