An Examination of Linkage of Schizophrenia and Schizoaffective Disorder to the Pseudoautosomal Region (Xp22.3)

1994 ◽  
Vol 164 (2) ◽  
pp. 159-164 ◽  
Author(s):  
Timothy J. Crow ◽  
Lynn E. Delisi ◽  
Raymond Lofthouse ◽  
Mark Poulter ◽  
Thomas Lehner ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Schizoaffective Disorder ◽  
Recombination Fraction ◽  
Sibling Pair ◽  
Pseudoautosomal Region ◽  
Dominant Model ◽  
Lod Score ◽  
Y Chromosomes ◽  
Pair Analysis

We investigated linkage between schizophrenia and the loci DXYS14, DXYS17, and MIC2 within the pseudoautosomal region in 85 families with two or more siblings suffering from schizophrenia or schizoaffective disorder. A maximum lod score of 2.44 was reached at MIC2, with a dominant model of inheritance at a recombination fraction of 0.367 in females and 0.046 in males (a F: M sex ratio > 1, i.e. opposite to that expected with a pseudoautosomal locus). Evidence consistent with linkage (P = 0.01) was also obtained with a sibling pair analysis at the MIC2 locus. These data do not support (although they do not definitively exclude) a locus within the pseudoautosomal region; they are consistent with the presence of a gene that predisposes to schizophrenia in the sex-specific regions of the X and Y chromosomes.

scholarly journals Sex ratio distortion in bovine sperm correlates to recombination in the pseudoautosomal region

2000 ◽  
Vol 75 (1) ◽  
pp. 53-59 ◽  
Author(s):  
JOANNA SZYDA ◽  
HENNER SIMIANER ◽  
SIGBJØRN LIEN
Keyword(s):  
Sex Ratio ◽  
Recombination Rate ◽  
Regression Models ◽  
Segregation Ratio ◽  
Pseudoautosomal Region ◽  
Logistic Regression Models ◽  
Bovine Sperm ◽  
Y Chromosomes ◽  
Ratio Distortion ◽  
Sex Ratio Distortion

A total of 2122 single sperm from 35 bulls belonging to six different paternal half-sib groups were analysed with respect to two markers in the bovine pseudoautosomal region (PAR) and sex- specific loci on the X and Y chromosomes, respectively. A segregation ratio significantly different from 1[ratio ]1 was observed in a test over all families, with a higher proportion of X-bearing gametes (53·5%). The analysis of recombination conducted separately for X- and Y-bearing sperm showed that X-bearing sperm cells possess highly significant individual and between-family variability in recombination rate, whereas Y-bearing sperm show linkage homogeneity. To test whether the two phenomena are related, different logistic regression models were fitted to the data. The results show that sex ratio significantly correlates with changes in recombination rate among X-bearing but not among Y-bearing sperm. Different hypotheses to explain these observations are discussed.

scholarly journals Biased Estimation of the Recombination Fraction Using Half-Sib Families and Informative Offspring

Genetics ◽  
2001 ◽  
Vol 157 (3) ◽  
pp. 1357-1367 ◽  
Author(s):  
L Gomez-Raya
Keyword(s):  
Recombination Fraction ◽  
Allele Frequencies ◽  
Likelihood Method ◽  
Simultaneous Estimation ◽  
Sampling Variance ◽  
Production Traits ◽  
Lod Score ◽  
Absolute Value ◽  
Sib Families ◽  
Map Distance

Abstract A maximum-likelihood method to estimate the recombination fraction and its sampling variance using informative and noninformative half-sib offspring is derived. Estimates of the recombination fraction are biased up to 20 cM when noninformative offspring are discarded. In certain scenarios, the sampling variance can be increased or reduced up to fivefold due to the bias in estimating the recombination fraction and the LOD score can be reduced up to 5 units when discarding noninformative offspring. Comparison of the estimates of recombination fraction, map distance, and LOD score when constructing a genetic map with 251 two-point linkage analyses and six families of Norwegian cattle was carried out to evaluate the implications of discarding noninformative offspring in practical situations. The average discrepancies in absolute value (average difference when using and neglecting noninformative offspring) were 0.0146, 1.64 cM, and 2.61 for the recombination fraction, map distance, and the LOD score, respectively. A method for simultaneous estimation of allele frequencies in the dam population and a transmission disequilibrium parameter is proposed. This method might account for the bias in estimating allele frequencies in the dam population when the half-sib offspring is selected for production traits.

The Continuum of Psychosis and Its Genetic Origins

1990 ◽  
Vol 156 (6) ◽  
pp. 788-797 ◽  
Author(s):  
T. J. Crow
Keyword(s):  
Sex Chromosome ◽  
Homo Sapiens ◽  
Polymorphic Marker ◽  
Cerebral Dominance ◽  
Homo Erectus ◽  
Evolutionary Development ◽  
Pseudoautosomal Region ◽  
Sibling Pairs ◽  
Homo Habilis ◽  
Y Chromosomes

Attempts to draw a line of genetic demarcation between schizophrenic and affective illnesses have failed. It must be assumed that these diseases are genetically related. A post-mortem study has demonstrated that enlargement of the temporal horn of the lateral ventricle in schizophrenia but not in Alzheimer-type dementia is selective to the left side of the brain. This suggests that the gene for psychosis is the ‘cerebral dominance gene‘, the factor that determines the asymmetrical development of the human brain. That the psychosis gene is located in the pseudoautosomal region of the sex chromosomes is consistent with observations that sibling pairs with schizophrenia are more often than would be expected of the same sex and share alleles of a polymorphic marker at the short-arm telomeres of the X and Y chromosomes above chance expectation. That the cerebral dominance gene also is pseudoautosomal is suggested by the pattern of verbal and performance deficits associated with sex-chromosome aneuploidies. The psychoses may thus represent aberrations of a late evolutionary development underlying the recent and rapid increase in brain weight in the transition fromAustralopithecusthroughHomo habilisandHomo erectustoHomo sapiens.

THE Y CHROMOSOMES OF DROSOPHILA SIMULANS ARE HIGHLY POLYMORPHIC FOR THEIR ABILITY TO SUPPRESS SEX-RATIO DRIVE

Evolution ◽  
2001 ◽  
Vol 55 (4) ◽  
pp. 728 ◽  
Author(s):  
Catherine Montchamp-Moreau ◽  
Valérie Ginhoux ◽  
Anne Atlan
Keyword(s):  
Sex Ratio ◽  
Drosophila Simulans ◽  
Y Chromosomes

scholarly journals Linkage and gene localization of hereditary spherocytosis (HS)

Blood ◽  
1978 ◽  
Vol 52 (5) ◽  
pp. 859-867 ◽  
Author(s):  
WJ Kimberling ◽  
RA Taylor ◽  
RG Chapman ◽  
HA Lubs
Keyword(s):  
Linkage Analysis ◽  
Hereditary Spherocytosis ◽  
Recombination Fraction ◽  
Gene Localization ◽  
Lod Score ◽  
Marker Loci

Abstract Fifteen kindreds with dominant hereditary spherocytosis (HS) were studied. Expansion of the data from a family with an 8/12 translocation provided further evidence that at least one locus for HS is located near the breakpoint of the translocation. Linkage analysis of all families showed a lack of linkage with all marker loci studied except for Gm (IgG). Linkage between Gm and HS was shown to be significant with a maximum lod score of 3.42 at a recombination fraction of 22%. No heterogeneity of the recombination fraction was observed either between sexes or between families. These results are compatible with the hypothesis that HS is not a heterogeneous disorder.

scholarly journals Human Spermatogenesis Tolerates Massive Size Reduction of the Pseudoautosomal Region

2020 ◽  
Vol 12 (11) ◽  
pp. 1961-1964
Author(s):  
Maki Fukami ◽  
Yasuko Fujisawa ◽  
Hiroyuki Ono ◽  
Tomoko Jinno ◽  
Tsutomu Ogata
Keyword(s):  
Animal Studies ◽  
Male Meiosis ◽  
Size Reduction ◽  
Pseudoautosomal Region ◽  
Minimal Size ◽  
Y Chromosomes ◽  
Cytogenetic Analyses ◽  
Human Spermatogenesis ◽  
Complete Deletion ◽  
Chromosomal Recombination

Abstract Mammalian male meiosis requires homologous recombination between the X and Y chromosomes. In humans, such recombination occurs exclusively in the short arm pseudoautosomal region (PAR1) of 2.699 Mb in size. Although it is known that complete deletion of PAR1 causes spermatogenic arrest, no studies have addressed to what extent male meiosis tolerates PAR1 size reduction. Here, we report two families in which PAR1 partial deletions were transmitted from fathers to their offspring. Cytogenetic analyses revealed that a ∼400-kb segment at the centromeric end of PAR1, which accounts for only 14.8% of normal PAR1 and 0.26% and 0.68% of the X and Y chromosomes, respectively, is sufficient to mediate sex chromosomal recombination during spermatogenesis. These results highlight the extreme recombinogenic activity of human PAR1. Our data, in conjunction with previous findings from animal studies, indicate that the minimal size requirement of mammalian PARs to maintain male fertility is fairly small.

Pseudoautosomal region in schizophrenia: Linkage analysis of seven loci by sib-pair and lod-score methods

1994 ◽  
Vol 52 (2) ◽  
pp. 135-147 ◽  
Author(s):  
Thierry d'Amato ◽  
Gilles Waksman ◽  
Maria Martinez ◽  
Claudine Laurent ◽  
Philip Gorwood ◽  
...  
Keyword(s):  
Linkage Analysis ◽  
Pseudoautosomal Region ◽  
Lod Score

Linkage of interleukin 6 locus to human osteopenia by sibling pair analysis

1999 ◽  
Vol 105 (3) ◽  
pp. 253-257 ◽  
Author(s):  
N. Ota ◽  
S.C. Hunt ◽  
T. Nakajima ◽  
T. Suzuki ◽  
T. Hosoi ◽  
...  
Keyword(s):  
Interleukin 6 ◽  
Sibling Pair ◽  
Pair Analysis

scholarly journals Linkage and gene localization of hereditary spherocytosis (HS)

Blood ◽  
1978 ◽  
Vol 52 (5) ◽  
pp. 859-867
Author(s):  
WJ Kimberling ◽  
RA Taylor ◽  
RG Chapman ◽  
HA Lubs
Keyword(s):  
Linkage Analysis ◽  
Hereditary Spherocytosis ◽  
Recombination Fraction ◽  
Gene Localization ◽  
Lod Score ◽  
Marker Loci

Fifteen kindreds with dominant hereditary spherocytosis (HS) were studied. Expansion of the data from a family with an 8/12 translocation provided further evidence that at least one locus for HS is located near the breakpoint of the translocation. Linkage analysis of all families showed a lack of linkage with all marker loci studied except for Gm (IgG). Linkage between Gm and HS was shown to be significant with a maximum lod score of 3.42 at a recombination fraction of 22%. No heterogeneity of the recombination fraction was observed either between sexes or between families. These results are compatible with the hypothesis that HS is not a heterogeneous disorder.

Sign in / Sign up

Export Citation Format

Share Document