Validity of the Zygosity Questionnaire and Characteristics of Zygosity-Misdiagnosed Twin Pairs in the Healthy Twin Study of Korea

2010 ◽  
Vol 13 (3) ◽  
pp. 223-230 ◽  
Author(s):  
Yun-Mi Song ◽  
Dong-Hun Lee ◽  
Mi Kyoung Lee ◽  
Kayoung Lee ◽  
Hee Jung Lee ◽  
...  
Keyword(s):  
Twin Study ◽  
Twin Pair ◽  
Correct Diagnosis ◽  
Striking Similarity ◽  
Genotype Information ◽  
Zygosity Questionnaire ◽  
Questionnaire Method ◽  
Short Tandem Repeat Markers ◽  
Mz Twins ◽  
Short Tandem

AbstractDetermining valid zygosity is a basic and important requirement in a twin study, because misdiagnosing zygosity leads to biased results. The Healthy Twin Study has collected data from adult like-sex twins and their families since 2005. In the study, a questionnaire to determine zygosity was developed comprising four questions; one concerning the degree of resemblance, and three concerning the degree of confusion by the resemblance. Among 2,761 individuals (624 twin pairs) of twin and their families, 406 pairs of twins (mean age 38.3, 63.5% women) with both questionnaire and genotype information were selected to examine the validity of the zygosity questionnaire using 16 short tandem repeat markers. We first determined individual zygosity including undetermined category, and then decided the zygosity of a twin pair using a decision tree. Sensitivity of questionnaire diagnosis was 98.8% for monozygotic (MZ) and 88.9% for dizygotic (DZ) twins, and positive predictive value was 97.2% for MZ and 95.0% for DZ. When we compared correctly and wrongly diagnosed twin pairs, misdiagnosed DZ twins (nine pairs) showed striking similarity in stature or obesity even exceeding that of true MZ twins. Our finding suggests that a parsimonious questionnaire method of diagnosing the zygosity will be useful, and adding physical or physiological measurements to a questionnaire of zygosity diagnosis will either confound the correct diagnosis or reduce the efficiency of the study compared with using questionnaire alone or with introducing genotyping.

scholarly journals Could Rapidly Mutating Y-STRs be a Potential Forensic Tool in Discriminating Lebanese Monozygotic Twins?

2018 ◽  
Vol 2 (2) ◽  
pp. 35
Author(s):  
Paula Romanos ◽  
Jamilah Borjac
Keyword(s):  
Twin Pair ◽  
Monozygotic Twins ◽  
Dna Profile ◽  
Identifiler Plus ◽  
Lineage Markers ◽  
Dna Profiles ◽  
Short Tandem Repeat Markers ◽  
Genetic Analyzer ◽  
Y Haplotype ◽  
Short Tandem

Despite the high power of discrimination that characterizes the well identified 16 to 24 autosomal short tandem repeat markers, monozygotic twins differentiation is generally limited. Arising from a single fertilized egg, monozygotic twins share the same genotype therefore the same DNA profile. This situation imposes a challenge in forensics especially considering that lineage markers are in general less informative than autosomal ones. Although in some cases Y haplotype is considered a powerful investigative tool, it cannot distinguish males belonging to the same paternal lineage.  The use of rapidly mutating Y-STRs with mutation rate above 1x10-2 that were recently included in forensic casework is presumed helpful. Since science is always dynamic and each population has its own characteristics, we aim in this study to distinguish between Lebanese monozygotic male twins using rapidly mutating Y-STRs. For this purpose, fourteen unrelated pairs of male monozygotic twins were recruited. Participants filled in a well-designed questionnaire and signed an informed consent. DNA was extracted using PureLink Genomic DNA Mini kit, genotyped using the Identifiler Plus kit, and separated on 3500 Genetic Analyzer to confirm the monozygosity status. DNA samples underwent a second amplification using the Y Filer Plus kit. According to our results, all the Y Filer Plus DNA profiles showed complete match for each twin pair. By consequence, the use of rapidly mutating Y-STRs in this study did not improve discrimination.

scholarly journals Oliver Sacks: Our Correspondence About Twins/Twin Research: Vanishing Twins Syndrome; Discordant Sex in MZ Twins; Pregnancy Outcomes in IVF and ICSI Conceived Twins/Print and Media: Superfetated Twins; Twins Discordant for Smoking; Twins in Fashion; Yale University Twin Hockey Players; Conjoined Twin–Visiting Professor

2017 ◽  
Vol 20 (4) ◽  
pp. 363-369
Author(s):  
Nancy L. Segal
Keyword(s):  
New York ◽  
Pregnancy Outcomes ◽  
Twin Pair ◽  
Multiple Pregnancy ◽  
New York Times ◽  
Yale University ◽  
Twin Research ◽  
Hockey Players ◽  
Vanishing Twin Syndrome ◽  
Mz Twins

The late neurologist and author, Oliver Sacks, published an insightful 1986 review of Marjorie Wallace's book, The Silent Twins, in the New York Times. Taking exception to his assertion about Sir Francis Galton, I wrote a letter to the Times’ editor. The letter was unpublished, but it brought a wonderful response from Sacks himself that is reproduced and examined. Next, brief reviews of twin research concerning the vanishing twin syndrome (VTS), discordant sex in a monozygotic (MZ) twin pair, and multiple pregnancy outcomes from assisted reproductive technology (ART) are presented. This section is followed by popular coverage of superfetated twins, smoking-discordant co-twins, twins in fashion, Yale University twin hockey players, and a visiting professor who was a conjoined twin.

scholarly journals The Host Genotype and Environment Affect Strain Types of Bifidobacterium longum subsp. longum Inhabiting the Intestinal Tracts of Twins

2015 ◽  
Vol 81 (14) ◽  
pp. 4774-4781
Author(s):  
Min Zhang ◽  
Xiaomin Hang ◽  
Jing Tan ◽  
Hong Yang
Keyword(s):  
Multilocus Sequence Typing ◽  
Twin Pair ◽  
Bifidobacterium Longum ◽  
Host Genotype ◽  
Content Type ◽  
Living Together ◽  
Adult Twins ◽  
The Impact ◽  
Mz Twins ◽  
Sequence Types

ABSTRACTTo investigate the influences of host genotype and environment onBifidobacterium longumsubsp.longuminhabiting human intestines at the strain level, six pairs of twins, divided into two groups (children and adults), were recruited. Each group consisted of two monozygotic (MZ) twin pairs and one dizygotic (DZ) twin pair. Child twins had been living together from birth, while adult twins had been living separately for 5 to 10 years. A total of 345B. longumsubsp.longumisolates obtained from 60 fecal samples from these twins were analyzed by multilocus sequence typing (MLST), and 35 sequence types (STs) were finally acquired. Comparison of strains within and between the twin pairs showed that no strains with identical STs were observed between unrelated individuals or within adult DZ twin pairs. Eight STs were found to be monophyletic, existing within MZ twins and child DZ twins. The similarity of strain types within child cotwins was significantly higher than that within adult cotwins, which indicated that environment was one of the important determinants inB. longumsubsp.longumstrain types inhabiting human intestines. However, although these differences between MZ and DZ twins were observed, it is still difficult to reach an exact conclusion about the impact of host genotype. This is mainly because of the limited number of subjects tested in the present study and the lack of strain types tracing in the same twin pairs from birth until adulthood.

Blood Glutathione and Cysteine Concentrations in Twin Children

2001 ◽  
Vol 226 (4) ◽  
pp. 349-352 ◽  
Author(s):  
Calvin A. Lang ◽  
Adam P. Matheny ◽  
Walter Mastropaolo ◽  
Marcia C. Liu
Keyword(s):  
Twin Study ◽  
Electrochemical Method ◽  
Environmental Influence ◽  
Healthy Children ◽  
Careful Attention ◽  
Blood Samples ◽  
Louisville Twin Study ◽  
Reduced And Oxidized Glutathione ◽  
Twin Children ◽  
Mz Twins

Glutathione and cysteine are major antioxidants in blood that are associated with health and longevity. To ensure their measurement, careful attention to avoid auto-oxidation is necessary to stabilize the samples. Since no report of these compounds has been reported in children, our goal was to determine their levels of reduced and oxidized glutathione (GSH and GSSG) and cysteine (Cys and CSSC), To this end, 140 healthy children, ages 2 to 9 years from the Louisville Twin Study were studied. Blood samples were collected and analyzed for GSH, GSSG, Cys, and CSSC by our HPLC dual electrochemical method. The results showed that GSH and total GSH (GSH + GSSG) levels for monozygotic (MZ) twins were significantly higher (P < 0.001) than levels for dizygotic (DZ) twins. However, the opposite occurred for Cys and total Cys (Cys + CSSC) in that the levels were significantly higher for DZ twins than for MZ twins. (P < 0.005-0.013). In spite of this marked difference in zygosity, the withinpair correlations for twin pairs used for estimating heritability suggested that there was a major environmental influence for total GSH and total Cys. Finally. GSH levels were significantly lower for young (2–9 years) children than adults (P < 0.001).

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