摘要:

The cytogenetic expression of fragile sites is highly variable. Sites are seen in differing proportions of cells. To determine if part of this variability is genetic, the proportions of lymphocytes manifesting the fragile X were examined in a large cohort of males with the fragile X chromosome. The number of fragile X cells was solely determined by genetic factors: the heritability as determined from the correlation between brothers as well as between cousins was 99.6% and 94.4%, respectively, as compared with 0% in unrelated males with the fragile X. This is consistent with pure genetic determination without any environmental influence over the expression of the fragile X chromosome in males.

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1986.tb00811.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

The determination of acetylcholinesterase (AChE) has been shown to be as specific as alphafeto‐protein (AFP) for the prenatal detection of open neural tube defects although AFP remains the method of choice. This paper describes a semi‐automated technique for the analysis of acetylcholinesterase in amniotic fluid that: A) reduces the cost of the procedure; B) allows for a larger number of samples to be run at a time; and C) provides for more accurate and reproducible procedures and results. Six fetuses with neural tube defects (2 with gastroschisis and 3 where one twin was dead) were detected and found to have elevated AChE, TChE and 2 bands by electrophoresis. Quality control procedures using both pure enzyme and amniotic fluid with low and high levels of the enzyme are described. The analysis of 340 amniotic fluids of normal pregnancies indicates that the normal value for AChE is 5.17 ± 2.63 mU/ml (97% confidence interval for the mean 4.84‐5.49 mU/ml. A group of 27 abnormal pregnancies provides evidence that fetal vomiting and regurgitation, fetal demise, multiple cysts syndrome, idiopathic IUGR, arthrogryposis multiplex, hydrocephaly (stenosis of aqueductus), trisomy 21, trisomy 18, hydronephrosis, pyloric stenosis, heart malformation, ectopia cordis and multiple gestation produce elevated levels of pseudocholinesterase (PChE) in amniotic fluid. The use of pseudocholinesterase levels in amniotic fluid for prenatal diagnosis is proposed and discussed in view of its elevated levels in abnormal pregnancies where AChE is normal. The normal values for PChE are 23.86 mU/ml (mean) and 5.83 for standard deviation. Electrophoretic analysis was performed on all samples with values higher than one standard deviation above the mean. The AChE band was found only in fetuses with open neural tube defects and pyloric st

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1986.tb00812.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

During three years, 39,924 infants born consecutively in the area covered by our registry of congenital malformations were surveyed; 775 had major congenital malformations.Recurrence risks for the major malformation was estimated and classified as high (>10%, 5.3% of the cases), low (1 to 10%, 85.3% of the cases) or occasional (<1%, 9.4% of the malformed).Feasibility of prenatal diagnosis was considered. On the basis of the recurrence risk of 1 % or higher and the feasibility of prenatal diagnosis, such a procedure should be considered in future pregnancies in 64.1% of the mothers.Genetic counseling has to be given to couples at risk of having a malformed child. For this purpose, as is shown in our study, the best way is the possibility of using a registry of congenital malformations.

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1986.tb00813.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

A significantly higher number of PI ZZ and PI MZ individuals was found in a flaccid lung population as compared to internal and healthy controls. The relative risk for ZZ is 12.5 and for MZ 1.8.We conclude that if a PI MZ individual does develop lung disease, the excess risk due to the deficiency is negligible compared to MM individuals and is highly influenced or modified by other factors, possibly including both environmental and genetic.

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1986.tb00814.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

On the basis of a Danish family material of Eiberg&Mohr (1981), especially 416 matings with 1595 children where the one parent has high activity of paraoxonase and the other low activity, and the 185 matings with 684 children where both parents have high activity, it is, by consideration of a two‐loci model and other alternatives besides the earlier suggested one‐locus model, confirmed that segregation into high and low activity is largely or exclusively due to a one‐locus system; in case any secondary locus is involved, its most common allele would probably have a frequency above

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1986.tb00815.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

An analysis of the findings in 21 patients with the Cowden syndrome or the multiple hamartoma syndrome is presented. The Cowden syndrome is a cancer‐associated genodermatosis with characteristic mucocutaneous findings and a wide array of associated abnormalities including a high incidence of breast cancer in female patients. Genetic studies confirmed autosomal dominant inheritance with a high penetrance in both sexes and moderate interfamilial and intrafamilial differences in the expressivity of a number of symptoms. Familial occurrence was present in 4 of the 7 families. There was a strong predominance of female patients (6:1), which may be fortuitous. Mucocutaneous changes were the most constant (100% incidence) and characteristic findings; they almost invariably became manifest in the second decade. Four of our 18 female patients (22%) were treated for breast cancer, a lower incidence than reported previously. No increased incidence of other types of malignancies was found. Craniomegaly (high head circumference) was found to be the most common extracutaneous manifestation (80% incidence); craniomegaly appears to be an important early marker. We also found high incidences of gastrointestinal polyps (approximately 60%) and cutaneous fibromas (76%), while the incidence of thyroid abnormalities, thus far regarded as the most common extracutaneous finding, was similar to that reported previously (62%). G‐banded karyotype and preliminary DNA‐repair studies revealed no clear abnormalities. No linkage with the loci of HLA, and immunoglobulin haplotypes was

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1986.tb00816.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

The apparently rare cytogenetic abnormality of partial trisomy 15 was diagnosed by the authors in a patient presenting with developmental retardation, macrocephaly with ventricular enlargement and prominent subarachnoid spaces, hypotonia, low‐set ears, hyperextensibJe wrists and hands, high arched palate, tapering fingers, right esotropia, and bilateral metatarsus adductus. Clinical findings in this case are similar to previously reported cases of proximal duplications of chromosome 15 and bear some similarity to the Prader‐Willi syndrome. However, our patient did not have the severe hypotonia, early failure to thrive, or genital abnormalities seen in classical Prader‐Willi syndrome. This case supports the theory that a variety of cytogenetic aberrations in proximal 15q can cause a “Prader‐Willi‐like” syndrome. Increased clinical suspicion is needed when patients are seen with hypotonia, retarded development and mild dysmorphism if the variety of phenotypes are to

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1986.tb00817.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

The nature and the origin of a supernumerary marker chromosome in a mentally retarded boy were determined by various staining techniques on metaphase chromosomes and by GBG high resolution technique. The karyotype was found to be 47, XY, + inv dup(15) (pter → q13: q13‐+pter) and the supernumerary chromosome was of maternal ori

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1986.tb00818.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

A second family showing transmission of a dicentric through three generations involving chromosomes 13 and 18 is presented. Features of non‐Robertsonian dicentric chromosomes are presented and discusse

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1986.tb00819.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

A newborn girl, homozygous for a balanced Y/22 chromosome translocation is described. This unique karyotype was detected during prenatal chromosome studies in the first pregnancy of a 26‐year‐old woman. Amniocentesis was performed because of clinical evaluation of severe fetal growth retardation in the 28th week of gestation. The cytogenetic results were confirmed using a lymphocyte culture after birth in the 30th week. Subsequent chromosome studies of the parents were hampered by the fact that the pregnancy was thought to be the result of artificial insemination with donorsperm. Nevertheless both, consanguineous, parents were shown to be carriers of the same, singular, chromosome translocation and the spermdonor could be excluded from paternity by bloodgroup‐ and HLA studies. Distamycin‐A‐DAPI chromosome staining and DNA studies of the mother were used to confirm the involvement of the Y‐chromosome in this translocation. The probanda is developing quite normally at the age o

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1986.tb00820.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY