scholarly journals  Allele frequency in loci which control coat colours in Hucul horse population

2012 ◽  
Vol 57 (No. 4) ◽  
pp. 178-186 ◽  
Author(s):  
A. Stachurska ◽  
A. Brodacki ◽  
J. Grabowska
Keyword(s):  
Genetic Structure ◽  
Allele Frequency ◽  
Global Strategy ◽  
Recessive Allele ◽  
Genotype Distribution ◽  
Horse Population ◽  
Wahlund Effect ◽  
Animal Genetic Resources ◽  
Genotype Frequencies ◽  
Its Gene

The objective of the study was to determine the frequency of alleles which produce coat colours in Hucul horse population in Poland. The breed is included in the Global Strategy for Management of Farm Animal Genetic Resources, hence its gene pool should remain in unaltered state. Huculs are bay, black, blue dun, yellow dun, tobiano, and chestnut. Grey and chestnut Huculs have always been undesirable. The material consisted of all 1022 matings which resulted in subpopulations recorded in Studbook volumes. The recessive allele frequency was estimated as the square root of recessive genotype frequencies in ASIP (A), MC1R (E), DUN (D), KIT (To region), and STX17 (G) loci. The frequency in A and E loci in total parental generation was also estimated in test matings. Genotype distribution in the population was anticipated according to gamete frequency in sires and dams. Small Wahlund effect, F<sub>ST</sub>and &chi;<sup>2</sup> values for allele distributions show that division into subpopulations did not influence the population genetic structure significantly. Mean recessive allele frequency in A, E, D, To, and G loci amounted to 0.521, 0.115, 0.878, 0.929, and 0.997, respectively, and in A and E loci it was similar to that assessed in test matings. More bay horses and fewer D diluted horses appeared in offspring than expected. A, e, d, and To allele frequency showed a rising tendency. The genetic structure in Hucul population is not constant and does not comply strictly with the preservation aim. Bay, non-diluted, and tobiano horses are preferred. The linkage between MC1R and KIT loci can make the selection against e allele difficult. Breeders&rsquo; preferences may lead to undesired changes in the allele frequency. To avoid such risk, it is recommended to select horses strictly complying with the rules included in the breeding programme and mate the horses randomly from this aspect. &nbsp;

scholarly journals Comparison of SNP Genotypes Related to Proliferative Vitreoretinopathy (PVR) across Slovenian and European Subpopulations

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Xhevat Lumi ◽  
Mateja M. Jelen ◽  
Daša Jevšinek Skok ◽  
Emanuela Boštjančič ◽  
Metka Ravnik-Glavač ◽  
...  
Keyword(s):  
Allele Frequency ◽  
Association Studies ◽  
Case Control ◽  
Genotype Distribution ◽  
Healthy Controls ◽  
Case Control Studies ◽  
Ensembl Database ◽  
Functional Polymorphisms ◽  
Genotype Frequencies ◽  
Frequency Changes

The present study investigated the distribution of genotypes within single nucleotide polymorphisms (SNPs) in genes, related to PVR pathogenesis across European subpopulations. Genotype distributions of 42 SNPs among 96 Slovenian healthy controls were investigated and compared to genotype frequencies in 503 European individuals (Ensembl database) and their subpopulations. Furthermore, a case-control status was simulated to evaluate effects of allele frequency changes on statistically significant results in gene-association studies investigating functional polymorphisms. In addition, 96 healthy controls were investigated within 4 SNPs: rs17561 (IL1A), rs2069763 (IL2), rs2229094 (LTA), and rs1800629 (TNF) in comparison to PVR patients. Significant differences (P<0.05) in distribution of genotypes among 96 Slovenian participants and a European population were found in 10 SNPs: rs3024498 (IL10), rs315952 (IL1RN), rs2256965 (LST1), rs2256974 (LST1), rs909253 (LTA), rs2857602 (LTA), rs3138045 (NFKB1A), rs3138056 (NFKB1A), rs7656613 (PDGFRA), and rs1891467 (TGFB2), which additionally showed significant differences in genotype distribution among European subpopulations. This analysis also showed statistically significant differences in genotype distributions between healthy controls and PVR patients in rs17561 of the IL1A gene (OR, 3.00; 95% CI, 0.77–11.75; P=0.036) and in rs1800629 of the TNF gene (OR, 0.48; 95% CI, 0.27–0.87; P=0.014). Furthermore, we have shown that a small change (0.02) in minor allele frequency (MAF) significantly affects the statistical p value in case-control studies. In conclusion, the study showed differences in genotype distributions in healthy populations across different European countries. Differences in distribution of genotypes may have had influenced failed replication results in previous PVR-related SNP-association studies.

Association of MDM2 Gene Polymorphisms SNP285 and 309 with Myelodysplastic Syndromes (MDS) Susceptibility and Outcome.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2823-2823
Author(s):  
Kathy L. McGraw ◽  
Lan Min Zhang ◽  
William Fulp ◽  
Hui-Yi Lin ◽  
Andres Jerez ◽  
...  
Keyword(s):  
Allele Frequency ◽  
Response Rate ◽  
Disease Onset ◽  
Response Duration ◽  
Negative Regulator ◽  
Genotype Distribution ◽  
Healthy Controls ◽  
Genotype Frequencies ◽  
Increased Risk ◽  
Significant Difference

Abstract Abstract 2823 Background: Mutations in TP53, or less often its regulators, increases risk for malignant transformation. Murine double minute protein 2 (MDM2), an E3 ubiquitin ligase, targets p53 for proteasomal degradation and is the most well studied negative regulator of p53. Recent investigations have highlighted the emerging importance of p53 in MDS. Haploinsufficiency for ribosomal protein S14 in deletion 5q MDS liberates free ribosomal proteins that bind to and promote degradation of MDM2, thereby activating p53 in erythroid precursors. A single nucleotide polymorphism (SNP) in an MDM2 promoter (SNP309) is linked to younger age of onset of several solid tumors and an increased risk for acute myeloid leukemia (AML) [Knappskog and Lonning. 2011. Transcription 2:207, Xiang et al. 2009. Leuk Res. 33:1454]. The thymine (T) to guanine (G) substitution introduces an additional Sp1 transcription factor binding site causing upregulation of MDM2 transcription. A second SNP in this promoter (SNP285) has also been linked to cancer susceptibility, where a guanine (G) to cytosine (C) exchange is associated with decreased ovarian and breast cancer risk (Knappskog and Lonning. 2011. Oncotarget. 2:251). The C-allele of SNP285 has diminished Sp1 promoter binding compared to the G-allele decreasing MDM2 expression. In this study we investigated genotype distribution of MDM2 SNPs in del(5q) and non-del(5q) MDS patients and compared results to healthy controls. Methods and Results: Using Sanger sequencing, we compared allele and genotype frequencies for SNP285 and SNP309 in 155 healthy controls, 97 non-del(5q), and 119 del(5q) MDS patients. For SNP285, we found no significant difference in genotype or allele frequency among non-del(5q) or del(5q) cases compared to controls (p=0.25 and 0.26, respectively). Although there was no difference in age at diagnosis by genotype in del(5q) MDS (p=0.82), there was a significant difference among non-del(5q) MDS cases [p<0.01, mean (range) for GC:80.8y (75–89) and GG:68.9y (27–91)], however, the frequency of the GC genotype was low [n=5, non-del(5q); n=11, del(5q)] with no CC genotype cases. For SNP309, there was no difference in allele frequency (p=0.68), however genotype frequency differed between controls, non-del5q, and del5q MDS (p=0.06). The genotype distribution was significantly different between non-del(5q) and del(5q) MDS (p=0.01). SNP309 genotype frequencies for controls, non-del(5q), and del(5q) MDS were GG:17.3%, 22.7%, 10.1%; TG: 42.9%, 37.1%, 53.8%; TT: 39.7%, 40.2%, 36.1%, respectively. We found no difference in age of disease onset by SNP309 genotype in either non-del(5q) or del(5q) cases (p=0.08 and 0.97, respectively). There was no significant relationship between SNP285 genotype and IPSS (p=1.0), cytogenetic risk (p=0.66), or WHO classification (p=0.16) in non-del(5q) or del(5q) cases (p=1.0, 0.78, and 0.60, respectively). Similar results were observed for SNP309 [p=0.85, 0.39, and 0.68 for non-del(5q); p= 0.06, 0.98, 0.27 for del(5q), respectively]. For SNP285 there was no difference in overall survival (OS) by genotype in either non-del(5q) (p=0.65) or del(5q) MDS (p=0.72). Progression free survival (PFS) also did not differ by genotype in non-del(5q) (p=0.82) or del(5q) (p=0.58) patients. There was a significant difference in LEN response rate in del(5q) MDS (p=0.04, non-responders: 23.8% GC and 76.2% GG, responders: 4.9% GC and 95.1% GG), however, genotype did not influence response duration (p= 0.40). For SNP309, there were no significant difference in OS by genotype (p=0.42), PFS (p=0.78), LEN response rate (p=0.17), or response duration in del(5q) MDS (p=0.65). In non-del(5q), there was no difference in OS (p=0.42), LEN response rate (p=0.91), or response duration (p=0.47). However, we found a significant difference in PFS by genotype (p=0.03) with more prolonged PFS in patients with the heterozygous TG genotype (60 mo PFS: GG 55.3%, TT 54.1%, and TG 81.7%). Finally, we found no difference in chromosome 5 deletion size or deletion location in del(5q) MDS according to SNP309 genotype. Conclusions: MDM2 SNP309 may be linked to MDS susceptibility, as well as LEN responsiveness and PFS in del(5q) and non-del(5q) MDS, respectively. These data warrant validation in a larger patient cohort. Investigation of the interaction between MDM2 SNPs and the well described TP53 R72P SNP is underway. Disclosures: List: Celgene: Consultancy.

scholarly journals CYP1A1 gene polymorphism among central Indian population and its genetic distribution

2016 ◽  
Vol 2 (1) ◽  
pp. 13 ◽  
Author(s):  
Snehlata Pandey ◽  
Arvind Tripathi ◽  
Jitendra Tripathi ◽  
Sanjeev Dubey
Keyword(s):  
Cytochrome P450 ◽  
Gene Polymorphism ◽  
Distribution Pattern ◽  
Allele Frequency ◽  
Urban Population ◽  
Polycyclic Hydrocarbon ◽  
P Value ◽  
Genotype Distribution ◽  
Genotype Frequencies ◽  
Cyp1a1 Gene

<p class="abstract"><strong>Background:</strong> The human gene, CYP1A1, encodes a member of the cytochrome P450 superfamily of enzymes. Cytochrome P450 (CYP1A1) enzymes are involved in the oxidative metabolism of endogenous compounds such as steroids, fatty acids, leukotrienes, prostaglandins, in the metabolism of foreign chemicals such as drugs, carcinogens, and other environmental pollutants and in polycyclic hydrocarbon metabolism. This was the first study done in the region of vindhyan Madhya Pradesh.</p><p class="abstract"><strong>Methods:</strong> The study population included total 300 samples from random population patients and normal healthy individuals (between 192 urban’s and 108 tribals). Physical data was collected during the sample collection.Genetic polymorphism study was carried out by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method and the observed genotype frequencies, allele frequencies and P- value for CYP1A1 gene polymorphism. All the statistical analyses were performed using spss software.</p><p class="abstract"><strong>Results:</strong> The genotype distribution pattern was not found different between tribal’s and urban population (χ2 =1.434 and P Value=0.4882) and overall allele frequency was also not statistically significant between two respective groups. Smoking and drinking activity data was generated through questionnaire organized during Sampling and the findings suggest that smoking have high effect over CYP1A1 gene polymorphism susceptibility.</p><strong>Conclusions: </strong>The genotype distribution pattern was not found different between tribal’s and urban population (χ2=1.434 and P Value=0.4882) and overall allele frequency was also not statistically significant between two respective groups.

Genetic structure and allele frequency dynamics in the sockeye salmon population of Lake Dalneye, Kamchatka

Aquaculture ◽  
1990 ◽  
Vol 84 (1) ◽  
pp. 13-25 ◽  
Author(s):  
V.S. Kirpichnikov ◽  
G.A. Muske ◽  
A.D. Scholl-Engberts ◽  
V.M. Chernov ◽  
S.N. Borchsenius
Keyword(s):  
Genetic Structure ◽  
Allele Frequency ◽  
Sockeye Salmon ◽  
Salmon Population

Analysing CYP2D6*4 Allele frequency in Patients with Schizophrenia

2017 ◽  
Vol 41 (S1) ◽  
pp. S101-S102
Author(s):  
V. Djordjevic ◽  
T. Jevtovic Stoimenov
Keyword(s):  
Allele Frequency ◽  
Plasma Concentrations ◽  
Clinical Severity ◽  
Genotype Distribution ◽  
Healthy Individuals ◽  
Wild Type ◽  
Specific Pcr ◽  
Significant Difference ◽  
Schizophrenic Patients ◽  
The Right

IntroductionSchizophrenia is treated with antipsychotics and other psychotropic medications, many of which are substrates for the highly polymorphic CYP2D6 enzyme. The most frequent variant allele is CYP2D6*4- leading cause of poor metabolism (PM) phenotype. PM causes the reduction of therapeutic response, increase the risk of adverse drug reactions and increase the plasma concentration of both drug and its metabolites above the levels of toxicity.The AimAnalysing CYP2D6*4 allele frequency among schizophrenic patients for further individualisation and rationalisation of therapy.Patients and methodsResearch was conducted on 38 schizophrenic patients and 110 healthy individuals. CYP2D6*4 allele was detected with allele specific PCR.ResultsBoth wild type allele carriers are 55% of the schizophrenic patients, 45% are wild type/*4heterozygous, and *4/*4 homozygous are not identified. There is a statistically significant difference in the genotype distribution (P < 0.05) between schizophrenic patients and healthy individuals. Significantly higher *4 allele frequency (37%) comparing to healthy individuals (P < 0.0001) indicates the necessary caution in administration of CYP2D6 substrates. A lower frequency of PMs in schizophrenic patients than in healthy individuals could be explained with CYP2D6 neuroactive substrate metabolism. Forty-five percent of the schizophrenic patients are intermediate metabolisers carrying the higher risk of adverse response to CYP2D6 substrates comparing to wild type homozygous. As none of the analyzed patients was PM, exceeded plasma concentrations of medications above toxic levels are not expected when administrating the right dosage.ConclusionAltered CYP2D6 metabolism may contribute to the vulnerability, clinical severity and treatment outcome of schizophrenia.Disclosure of interestThe authors have not supplied their declaration of competing interest.

scholarly journals GENETIC STRUCTURE OF HORSES POPULATION FOR THE GENES OF SCID AND HYPP

2017 ◽  
Vol 53 ◽  
pp. 248-253
Author(s):  
E. S. Cheburanova ◽  
O. A. Epishko ◽  
T. I. Kuzmina
Keyword(s):  
Genetic Structure ◽  
Severe Combined Immunodeficiency ◽  
Genetic Diagnosis ◽  
Hereditary Disease ◽  
Periodic Paralysis ◽  
Combined Immunodeficiency ◽  
Hyperkalemic Periodic Paralysis ◽  
Horse Population ◽  
Horse Farms ◽  
The Republic

Objective: identification of carrier animals of the hereditary anomaly SCID and HYPP of the population of horses bred on breeding horse farms of the Republic of Belarus. Methods: genetic, biological. DNA diagnosis of genotypes in the gene severe combined immunodeficiency (SCID) and hyperkaliemic periodic paralysis (HYPP) was performed using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) in the research laboratory «DNA Technology» of educational establishment «Grodno State Agrarian University». We tested 50 horses of different breeds, kept on different breeding horse farms of Belarus. DNA was isolated from buccal epithelium by perchlorate method with double purification (according to the method of Zinovieva). A study of the genetic structure of the horse population for hereditary anomalies of severe combined immunodeficiency and hyperkalemic periodic paralysis was performed using modern equipment. Amplification was carried out using the C1000 Touch thermal cycler (BioRad, USA). The visualization of the gel was carried out using the gel-documenting system Gel Doc XR + (Bio- Rad, USA). Main results. The use of modern methods for the genetic diagnosis of hereditary diseases of agricultural animals not only at birth to exclude from the process of reproduction of animal carriers of hereditary anomalies, but also reduces funding for their maintenance and cultivation. In the studies we used the PCR method based on the use of specific oligonucleotides with which the amplification of the necessary fragment of the 163 gene occurs in healthy individuals and 158 in the mutation carriers, which makes it possible to identify the hereditary SCID disease. We tested 50 animals of the upper and Arabian breeds, as well as horses with an admixture of Arabian blood, among which no carriers of the hereditary anomaly were found. In studies, the PCR-RFLP analysis method was used, based on the use of distinctive primers due to which the necessary fragment of the gene is amplified, which makes it possible to identify the hereditary HYPP disease. Amplified fragments were subjected to the action of restriction enzymes, with the help of which it is possible to determine the genotype of the animal under study. We tested 50 animals of the upper and Arabian breeds, as well as horses with an admixture of Arabian blood, among which no carriers of the hereditary anomaly were found. Conclusions. Severe combined immunodeficiency (SCID) is an autosomal recessive disease that occurs in humans, mice, horses and dogs. Carriers of this hereditary disease are born without visible anomalies, but after 2 weeks they become ill from any infection and die, since they can not develop an antigen-specific immune response. Hyperkaliemic periodic paralysis (HYPP) is an autosomal dominant disease that occurs in horses at the age of 2, when the animal begins, is strengthened to exercise. Symptoms of this disease are weakness of the muscles, periodic spasms, paralysis, which can lead to death. Presumably, there were no carriers of severe combined immunodeficiency in the Republic of Belarus, since breeding farms for breeding horses did not use biological material of Arabian and local breeds of horses for insemination. With subsequent importation of Arabian horses, as well as breeds that have an admixture of Arab blood, it is necessary to conduct DNA testing for the presence of severe combined immunodeficiency (SCID). According to the results of the conducted studies to identify the hereditary disease of hyperkalemic periodic paralysis (HYPP) in the horse population, no carriers were found, as well as sick animals. Presumably, there were no carriers of this disease on the territory of the republic, as evidenced by parallel studies conducted in other European countries, where no carrier or sick animal was found. This suggests that the disease was localized during the time, and also did not leave the territory of the American continent.

scholarly journals Evaluation of PECAM-1 Gene Polymorphism in Patients with Periodontal Disease and Healthy Individuals

2012 ◽  
Vol 2012 ◽  
pp. 1-5
Author(s):  
Mahdi Kdkhodazadeh ◽  
Mehrdad Hajilooi ◽  
Behzad Houshmand ◽  
Sara Khazaei ◽  
Leila Gholami ◽  
...  
Keyword(s):  
Chronic Periodontitis ◽  
Aggressive Periodontitis ◽  
Genotype Distribution ◽  
Nucleotide Polymorphisms ◽  
Healthy Individuals ◽  
Single Nucleotide ◽  
Genotypic Distribution ◽  
Genotype Frequencies ◽  
Significant Difference ◽  
Polymerase Chain

Objective. Our aim in this paper was to investigate the possible genetic association between three Ser563Asn, Leu125Val and Arg670Gly polymorphisms of the PECAM-1 gene and periodontitis. Methods. Genomic DNA was isolated from whole blood of 105 periodontal patient (52 with chronic periodontitis and 53 with aggressive periodontitis) and 101 healthy individuals. Samples were genotyped and analyzed for the three single-nucleotide polymorphisms (SNPs) of PECAM-1 using polymerase chain reaction with sequence-specific primers (PCR-SSPs). Results. A statistically significant difference was found between the genotypic distribution of the Ser563Asn polymorphism in patients with periodontitis compared to controls (P=0.02). But there were no statistically significant difference between the allele frequencies in the different groups (P=0.05). The other two polymorphisms did not show a statistically significant difference in their allele and genotype frequencies between the groups. There was no statistically significant difference found for any of the polymorphisms allele and genotype distribution in aggressive and chronic periodontitis either. Conclusions. No significant association was found between the polymorphism tested and the subgroups of periodontitis, further research is still necessary to determine whether this polymorphism can be used as a genetic marker of periodontitis.

scholarly journals Geographic patterns of human allele frequency variation: a variant-centric perspective

2020 ◽  
Author(s):  
Arjun Biddanda ◽  
Daniel P. Rice ◽  
John Novembre
Keyword(s):  
Genetic Variation ◽  
Gene Flow ◽  
Genetic Structure ◽  
Allele Frequency ◽  
Human Genetics ◽  
Geographic Region ◽  
Frequency Variation ◽  
Human Genetic Variation ◽  
Alternative Representation ◽  
Geographic Patterns

AbstractA key challenge in human genetics is to describe and understand the distribution of human genetic variation. Often genetic variation is described by showing relationships among populations or individuals, in each case drawing inferences over a large number of variants. Here, we present an alternative representation of human genetic variation that reveals the relative abundance of different allele frequency patterns across populations. This approach allows viewers to easily see several features of human genetic structure: (1) most variants are rare and geographically localized, (2) variants that are common in a single geographic region are more likely to be shared across the globe than to be private to that region, and (3) where two individuals differ, it is most often due to variants that are common globally, regardless of whether the individuals are from the same region or different regions. To guide interpretation of the results, we also apply the visualization to contrasting theoretical scenarios with varying levels of divergence and gene flow. Our variant-centric visualization clarifies the major geographic patterns of human variation and can be used to help correct potential misconceptions about the extent and nature of genetic differentiation among populations.

scholarly journals An Interdependence between Estrogen Receptor 1 Gene Polymorphisms and Susceptibility to Breast Cancer

2021 ◽  
Vol In Press (In Press) ◽  
Author(s):  
Maryam Saneipour ◽  
Abdolkarim Sheikhi ◽  
Abbas Moridnia
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Allele Frequency ◽  
Genetic Alterations ◽  
Recessive Model ◽  
Control Group ◽  
Genotype Distribution ◽  
Increased Risk ◽  
Significant Difference ◽  
Estrogen Receptor 1

Background: Breast cancer (BC) is the most common malignant tumor in women around the world. Genetic factors do play a vital role in the development and progression of BC. Genetic alterations in the ESR1 (estrogen receptor 1) gene can lead to estrogen dysfunction and increased risk for BC. Nevertheless, due to genetic diversity, the information from different studies is contradictory and controversial. Objectives: This study aimed to investigate the potential relationship between the rs1801132 and rs2234693 single nucleotide polymorphism (SNPs) of the ESR1 gene with susceptibility to BC in the Iranian population. Methods: The genotyping of the rs2234693 and rs1801132 SNPs was assessed in 63 BC patients referred to Imam Hasan Mojtaba Center, which is a charity-based foundation for cancer care in Dezful, Iran, from March 2018 to November 2019. Also, 65 healthy women were selected as a control group. The genotyping of the SNPs was performed using the high-resolution melting (HRM) technique and confirmed by DNA sequencing. Results: The genotype distribution and allele frequency of the rs2234693 SNP were significantly different in BC patients compared to the control group (genotype frequency with P = 0.018 and allele frequency with P = 0.004, OR = 2.085, 95% CI = 1.253 -3.468). In genetic models, rs2234693 increased BC risk in recessive model (P = 0.005, OR = 2.813, 95% CI = 1.363 - 5.802). However, there was no significant difference regarding genotype distribution of the rs1801132 SNP between the BC patients and controls. Conclusions: Our results showed that the CC genotype of the rs2234693 SNP is significantly associated with BC. Accordingly, it can be suggested that the rs2234693 SNP be considered for susceptibility to BC.

Estimation of genotype distributions and posterior genotype probabilities for beta-mannosidosis in Salers cattle.

Genetics ◽  
1993 ◽  
Vol 135 (3) ◽  
pp. 855-868
Author(s):  
J F Taylor ◽  
B Abbitt ◽  
J P Walter ◽  
S K Davis ◽  
J T Jaques ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Medical Diagnostics ◽  
Relative Fitness ◽  
Model Parameters ◽  
Genotype Distribution ◽  
Lysosomal Storage ◽  
Genotypic Distribution ◽  
Genotype Assignment ◽  
Genotype Frequencies ◽  
Systematic Effects

Abstract beta-Mannosidosis is a lethal lysosomal storage disease inherited as an autosomal recessive in man, cattle and goats. Laboratory assay data of plasma beta-mannosidase activity represent a mixture of homozygous normal and carrier genotype distributions in a proportion determined by genotype frequency. A maximum likelihood approach employing data transformations for each genotype distribution and assuming a diallelic model of inheritance is described. Estimates of the transformation and genotype distribution parameters, gene frequency, genotype fitness and carrier probability were obtained simultaneously from a sample of 2,812 observations on U.S. purebred Salers cattle with enzyme activity, age, gender, month of pregnancy, month of testing, and parents identified. Transformations to normality were not required, estimated gene and carrier genotype frequencies of 0.074 and 0.148 were high, and the estimated relative fitness of heterozygotes was 1.36. The apparent overdominance in fitness may be due to a nonrandom sampling of progeny genotypes within families. The mean of plasma enzyme activity was higher for males than females, higher in winter months, lower in summer months and decreased with increased age. Estimates of carrier probabilities indicate that the test is most effective when animals are sampled as calves, although effectiveness of the plasma assay was less for males than females. Test effectiveness was enhanced through averaging repeated assays of enzyme activity on each animal. Our approach contributes to medical diagnostics in several ways. Rather than assume underlying normality for the distributions comprising the mixture, we estimate transformations to normality for each genotype distribution simultaneously with all other model parameters. This process also excludes potential biases due to data preadjustment for systematic effects. We also provide a method for partitioning phenotypic variation within each genotypic distribution which allows an assessment of the value of repeat measurements of the predictive variable for genotype assignment.

Sign in / Sign up

Export Citation Format

Share Document