Sequence polymorphism of the mitochondrial DNA hypervariable regions I and II in 205 Singapore Malays

Mitochondrial DNA sequences of the hypervariable regions HV1 and HV2 were analyzed in 205 unrelated ethnic Malays residing in Singapore as an initial effort to generate a database for forensic identification purposes. Sequence polymorphism was detected using PCR and direct sequencing analysis. A total of 152 haplotypes was found containing 152 polymorphisms. Out of the 152 haplotypes, 115 were observed only once and 37 types were seen in multiple individuals. The most common haplotype (16223T, 16295T, 16362C, 73G, 146C, 199C, 263G, and 315.1C) was shared by 7 (3.41%) individuals, two haplotypes were shared by 4 individuals, seven haplotypes were shared by 3 individuals, and 27 haplotypes by 2 individuals. Haplotype diversity and random match probability were estimated to be 0.9961% and 0.87%, respectively.     

Sequence polymorphisms of mtDNA HV1, HV2, and HV3 regions in the Malay population of Peninsular Malaysia

The uniparentally inherited mitochondrial DNA (mtDNA) is in the limelight for the past two decades, in studies relating to demographic history of mankind and in forensic kinship testing. In this study, human mtDNA hypervariable segments 1, 2, and 3 (HV1, HV2, and HV3) were analyzed in 248 unrelated Malay individuals in Peninsular Malaysia. Combined analyses of HV1, HV2, and HV3 revealed a total of 180 mtDNA haplotypes with 149 unique haplotypes and 31 haplotypes occurring in more than one individual. The genetic diversity was estimated to be 99.47%, and the probability of any two individuals sharing the same mtDNA haplotype was 0.93%. The most frequent mtDNA haplotype (73, 146, 150, 195, 263, 315.1C, 16140, 16182C, 16183C, 16189, 16217, 16274, and 16335) was shared by 11 (4.44%) individuals. The nucleotide diversity and mean of pair-wise differences were found to be 0.036063 ± 0.020101 and 12.544022 ± 6.230486, respectively.     

Sequence polymorphism of mitochondrial DNA in Japanese individuals from Gifu Prefecture

Sequence polymorphisms of the hypervariable region HV1 in mitochondrial DNA (mtDNA) were analyzed in a sample of 137 unrelated Japanese individuals living in Gifu Prefecture (central region of Japan) using polymerase chain reaction amplification and direct sequencing. Eighty-two different haplotypes resulting from 81 variable sites were found in the mtDNA HV1 region between positions 16061 and 16450. The most frequent haplotype (16223T, 16362C) was shared by ten individuals. The genetic diversity and the genetic identity were 0.985 and 0.022, respectively. The C-stretch region located around position 16189 was observed in 23.4% of this population sample. Sequence heteroplasmy at the position 16103 (A/G) was found in one individual.     

Sequence analysis of mitochondrial DNA hypervariable region I in Thai individuals

Nucleotide sequence analysis of hypervariable region I (HVRI) in human mitochondrial DNA (mtDNA) was investigated in 100 unrelated Thai individuals. A total of 85 variable sites and 423 base substitutions, which consisted of 390 nucleotide transitions and 33 nucleotide transversions were found. The following nucleotide substitutions were found: 48% at 16,223, 31% at 16,304, 30% at 16,332, and 26% at 16,129, respectively. Transition from T to C (43.7%) was the most frequent substitution. The nucleotide insertions were found at two sites with T at position 16,188 and C at position 16,194. Eighty-two haplotypes were investigated of which 72 haplotypes were unique. The most frequent haplotypes (16,108T-16,129A-16,162G-16,172C-16,304C and 16,260T-16,298C-16,355T-16,362C) were observed. From position 16,180 to 16,193, thirteen patterns of polycytosine or C-stretch were observed, whereas 68 Thai individuals were found to be similar to the references. The genetic diversity, random match probability, and discrimination power were estimated to be 0.9943, 0.0156, and 0.9844, respectively.     

Mitochondrial DNA hypervariable region 1 polymorphism in Singapore Chinese population

Sequence polymorphisms of hypervariable region 1 were analyzed in 100 unrelated Singaporean Chinese. Ninety-five different haplotypes resulting from 113 variable sites were found between nucleotide positions 16045 and 16364. Single nucleotide polymorphism at nucleotide positions 16223, 16045, 16129, 16362 and 16189 was amongst the five highest frequencies observed in the sequences, whilst the most frequent haplotype was 16045-16223. Based on polymorphic sites observed at HV1, haplogroups A, F1a, M7b1, B5a and D4b were the most commonly observed clusters. The haplotype, nucleotide diversity and the average number of nucleotide differences were found to be 0.999, 0.028 and 9.082, respectively. The cytosine-stretch region located around nucleotide position 16189 was observed in 22% of this population sample. Transitions were found to be more predominant than transversions.     

Sequence polymorphism of the mitochondrial DNA control region in the Slovenian population

The forensic application of mitochondrial DNA (mtDNA) typing requires large and regionally well-defined databases. To expand the database for forensic identification purposes in Slovenia, the mtDNA control region sequences of the hypervariable regions HVI and HVII were determined in a population of 129 maternally unrelated Slovenians, using a fluorescent-based capillary electrophoresis sequencing method. A total of 111 different haplotypes resulting from 124 polymorphic positions (80 polymorphic positions in HVI and 44 in HVII) were found. Of these, 101 mtDNA types were unique, 6 haplotypes were shared by 2 individuals, 1 haplotype by 3 individuals, 2 haplotypes by 4 individuals, and the most common haplotype was found in 5 individuals. The most frequent haplotypes in the Slovenian population ,263(G), 315.1(C) and 263(G), 309.1(C), 315.1(C) are also the most common in other European populations. The data support the concept that these haplotypes may represent a common European mtDNA sequence types. The sequence poymorphisms were compared to the databases of west Austria and central Italy and the HVI and HVII sequence matching probabilities within and between populations were calculated. It is 1.1–4.5 times more likely to find a sequence match in a random pair of Slovenians than in a random Slovenian-Italian pair and in a random Slovenian-Austrian pair. The length heteroplasmy in the homopolymeric C-stretch regions located at nucleotide positions 16184–16193 in HVI and at positions 303–315 in HVII was observed in 17% and 8% of individuals, respectively. A statistical estimate of the results for this population showed the random match probability and the genetic diversity of 1.16% and 0.996, respectively.Electronic Supplementary Material Supplementary material is available in the online version of this article at http://dx.doi.org/10.1007/s00414-003-0394-3     

Polymorphism of the mitochondrial DNA control region in Italians

Mitochondrial DNA sequences of the hypervariable regions HVI and HVII were analysed in 83 Caucasians living in central Italy to expand the database for forensic identification purposes, and 75 different haplotypes resulting from 62 polymorphic positions in HVI and 44 in HVII were observed. The most frequent haplotype (263G, 309.1C, 315.1C) was shared by 7 individuals, 2 haplotypes were shared by 2 individuals, and 72 were unique. The genetic diversity was found to be 0.99 and the random match probability 1.9%. A condition of sequence heteroplasmy was found in only one case at nt 16311, whereas a length heteroplasmy was found in the homopolymeric stretch of cytosines 303–315. Our results indicate that in direct sequencing beyond the poly-cytosine stretch, the overlap is due to length heteroplasmy, whereas the blurred signal occurs when the stretch is composed of more than 10 cytosines. Received: 14 February 2000 / Accepted: 23 May 2000     

Sequence polymorphisms of mtDNA HV1, HV2 and HV3 regions in eight population groups living in Taiwan

Analysis of human mitochondrial DNA (mtDNA) polymorphisms in the D-loop region has become a useful tool in forensic casework and matrilineal origin research. In this study, the mtDNA D-loop region including hypervariable region 1 (HV1), hypervariable region 2 (HV2), segment between HV1 and HV2 (7S DNA spanned region), and extended hypervariable region 3 (HV3ex) was sequenced in 539 unrelated individuals from eight population groups living in Taiwan. Combined analyses of the complete D-loop revealed a total of 383 haplotypes with 319 unique haplotypes. The probability of any two individuals sharing the same mtDNA haplotype decreased as the combination of control region segments extended and reached 0.48% with the combination of a complete D-loop region. Sequence variants in HV3ex can further discriminate the haplotypes in some population groups. Phylogenetic haplogroups of these subjects were analyzed. The multidimensional scaling plots of these population groups, constructed based on sequence of the complete D-loop, demonstrated a clear matrilineal genetic substructure in this area. In conclusion, this database of mtDNA complete D-loop sequence including HV3 can serve as a reference for forensic identification. Sequence polymorphisms of the D-loop located outside the HV1 and HV2 may be helpful in further haplogroup characterization.     

Italian mitochondrial DNA database: results of a collaborative exercise and proficiency testing

This work is a review of a collaborative exercise on mtDNA analysis undertaken by the Italian working group (Ge.F.I.). A total of 593 samples from 11 forensic genetic laboratories were subjected to hypervariable region (HVS-I/HVS-II) sequence analysis. The raw lane data were sent to MtDNA Population Database (EMPOP) for an independent evaluation. For the inclusion of data for the Italian database, quality assurance procedures were applied to the control region profiles. Only eight laboratories with a final population sample of 395 subjects passed the quality conformance test. Control region haplogroup (hg) assignments were confirmed by restriction fragment length polymorphism (RFLP) typing of the most common European hg-diagnostic sites. A total of 306 unique haplotypes derived from the combined analysis of control and coding region polymorphisms were found; the most common haplotype--CRS, 263, 309.1C, 315.1C/ not7025 AluI--was shared by 20 subjects. The majority of mtDNAs detected in the Italian population fell into the most common west Eurasian hgs: R0a (0.76%), HV (4.81%), H (38.99%), HV0 (3.55%), J (7.85%), T (13.42%), U (11.65%), K (10.13%), I (1.52%), X (2.78%), and W (1.01%).     

Discrimination of haplotype in mitochondrial DNA mixtures using LNA-mediated PCR clamping

Locked nucleic acid (LNA) has been widely used for various genetic analyses, and has many benefits, in terms of the specificity or sensitivity of amplification, because LNA-containing primers/probes form more stable duplexes with template DNA than probes lacking LNA. Here, we developed a new method for discriminating HV1 haplotypes from mitochondrial DNA (mtDNA) mixtures by applying PCR clamping using LNA. PCR clamping is based on the selective inhibition of amplification using LNA-containing probes, which can discriminate single-nucleotide differences. Before designing probes, we selected 171 sequences with single-nucleotide variations from the HV1 region, and evaluated the specificity of LNA-containing probes for them by predicting Tm values. The differences of Tm between mismatched and exactly matched probe–template duplexes depended markedly on the type of LNA nucleotides for discriminating single-nucleotide differences, and the cytosine LNA nucleotide at the site of variations in the probes was most effective to discriminate these differences. For mixture analysis, each probe targeted one or two variations (16209C, 16217C, 16257A/16261T, 16297C/16298C, 16304C, 16362C, or 16362T) that are particularly common in the Japanese population, and seven designed probes completely inhibited the amplification of exactly matched templates. We prepared mixed samples by mixing DNA from two individuals at a ratio of 1:9, 1:4, 1:1, 4:1, or 9:1, and then performed Sanger sequencing analysis after PCR clamping with each probe. Our method distinguished each haplotype at lower ratios from two-person mixtures, and enabled sensitive detection at 12 pg of total DNA including 600 copies of mtDNA. Moreover, we analyzed three-person mixtures with representative sequences, and detected the minor haplotype of one individual present at a rate of 10% by adding two selected probes. The ability to discriminate haplotypes in mixed samples by using LNA-mediated PCR clamping indicates the potential value of mtDNA analysis in criminal investigations.     

Helena,the hidden beauty: Resolving the most common West Eurasian mtDNA control region haplotype by massively parallel sequencing an Italian population sample

The analysis of mitochondrial (mt)DNA is a powerful tool in forensic genetics when nuclear markers fail to give results or maternal relatedness is investigated. The mtDNA control region (CR) contains highly condensed variation and is therefore routinely typed. Some samples exhibit an identical haplotype in this restricted range. Thus, they convey only weak evidence in forensic queries and limited phylogenetic information. However, a CR match does not imply that also the mtDNA coding regions are identical or samples belong to the same phylogenetic lineage. This is especially the case for the most frequent West Eurasian CR haplotype 263G 315.1C 16519C, which is observed in various clades within haplogroup H and occurs at a frequency of 3–4% in many European populations.In this study, we investigated the power of massively parallel complete mtGenome sequencing in 29 Italian samples displaying the most common West Eurasian CR haplotype – and found an unexpected high diversity. Twenty-eight different haplotypes falling into 19 described sub-clades of haplogroup H were revealed in the samples with identical CR sequences. This study demonstrates the benefit of complete mtGenome sequencing for forensic applications to enforce maximum discrimination, more comprehensive heteroplasmy detection, as well as highest phylogenetic resolution.     

Haplotype diversity in mitochondrial DNA hypervariable region in a population of southeastern Brazil

Brazilian population derives from Native Amerindians, Europeans, and Africans. Southeastern Brazil is the most populous region of the country. The present study intended to characterize the maternal genetic ancestry of 290 individuals from southeastern (Brazil) population. Thus, we made the sequencing of the three hypervariable regions (HV1, HV2, and HV3) of the mitochondrial DNA (mtDNA). The statistical analyses were made using Arlequin software, and the median-joining haplotype networks were generated using Network software. The analysis of three hypervariable regios showed 230 (79.3 %) unique haplotypes and the most common haplotype was “263G” carried by 12 (4.1 %) individuals. The strikingly high variability generated by intense gene flow is mirrored in a high sequence diversity (0.9966?±?0.0010), and the probability of two random individuals showing identical mtDNA haplotypes were 0.0068. The analysis of haplogroup distribution revealed that 36.9 % (n?=?107) presented Amerindian haplogroups, 35.2 % (n?=?102) presented African haplogroups, 27.6 % (n?=?80) presented European haplogroups, and one (0.3 %) individual presented East Asian haplogroup, evidencing that the southeastern population is extremely heterogeneous and the coexistence of matrilineal lineages with three different phylogeographic origins. The genetic diversity found in the mtDNA control region in the southeastern Brazilian population reinforces the importance of increased national database in order to be important and informative in forensic cases.     

Sequence polymorphism of the mitochondrial DNA control region in the population of Vojvodina Province,Serbia

In order to generate and establish the database for forensic identification purposes in Vojvodina Province (Serbia), the sequence of the hypervariable regions 1 (HV1) and 2 (HV2) of the mtDNA control region were determined in a population of 104 unrelated individuals from Vojvodina Province, using a fluorescent-based capillary electrophoresis sequencing method. A total of 93 different haplotypes were found, of these 83 mtDNA types were unique, nine haplotypes were shared by two individuals and one haplotype by three individuals. The variation of mtDNA HV1 and HV2 regions was confined to 116 nucleotide positions, of which 72 were observed in the HV1 and 44 in the HV2. A statistical estimate of the results for this population showed the genetic diversity of 0.9977 and the random match probability of 1.18%. Haplogroup H was the most common haplogroup (43.3%). Haplogroups observed at intermediate levels included clusters U (13.5%), T (10.6%), J (8.6%) and W (5.8%).     

Base specific variation rates at mtDNA positions 16093 and 16183 in human hairs

Small variations between haplotypes detected in different tissues from the same individual have been previously described. These differences complicate the interpretation of mtDNA results in real forensic casework. mtDNA haplotypes detected in hair strands collected at the crime scene have to be frequently compared with haplotypes of reference samples (buccal swabs) from victims or suspects. Nucleotide position 16093 is a well-known hot spot where differences can accumulate between different tissues of the same individual. Intra individual variation was also detected at positions 16182 and 16183 in haplotypes showing an uninterrupted HV1 poly-C stretch (with 16189C).In order to better characterize the type of variation in these positions between buccal cells and hair strands from the same individual, we have performed Sanger sequencing in 25–28 hair strands (411 in total) from 15 individuals showing either an uninterrupted HV1 polyC-stretch (16189C) or 16093C/Y in their buccal cells. The results have been evaluated by also taking into account our previous results published in [19]. We have found that no variation among hair strands was detected in individuals showing T16093 in buccal cells, while variation in hair strands (T16093, 16093C and 16093Y) were detected in individuals showing 16093C or 16093Y in buccal cells. Regarding nucleotide positions 16182 and 16183 in combination with an uninterrupted polyC-stretch, no variation was detected in hairs from individuals showing A16182 16183C in their buccal cells. In contrast, individuals A16182 A16183 showed hair strands with A16182 16183 M and A16182 16183C. And finally, individuals with 16182C 16183C showed some variation in a small amount of their hair strands (some hairs with 16182 M 16183C). These results can be relevant for forensic practitioners when comparing reference samples with hair strands, which is the type of sample most tested by using mtDNA analysis in forensic casework.     

The results of an mtDNA study of 1200 inhabitants of a German village in comparison to other Caucasian databases and its relevance for forensic casework

Mitochondrial DNA control region sequences were determined in 1200 male volunteers from one village area of Lower Saxony for the hypervariable region 1 (HV1). The 154 variable positions found resulted in 460 different haplotypes with a haplotype diversity value of 0.98165. The number of different haplotypes showed a nearly linear increase with the number of individuals typed. The haplotype diversity approached saturation level at a value of approximately 0.981 after typing 400 individuals. Furthermore, the number of different haplotypes and the haplotype diversity were calculated for four short amplicons of HV1 in order to establish the most variable section with a high efficiency for forensic casework. Received: 29 January 2000 / Accepted: 24 April 2000     

Nucleotide sequence analysis of the hypervariable region III of mitochondrial DNA in Thais

This study analyzed the nucleotide sequences of the hypervariable region III (HVRIII) of mitochondrial DNA in Thai individuals. Buccal swab samples were randomly obtained from 100 healthy, unrelated, adult (18–60 years old), volunteer donors living in Thailand. Eighteen different haplotypes were found, of which 11 haplotypes were unique. The most frequent haplotypes observed were 522D-523D. Nucleotide transition from Thymine (T) to Cytosine (C) at position 489 (43%) was the most frequent substitution. Nucleotide transversions were also observed at position 433 (Adenine (A) to C, 1%) and position 499 (Guanine (G) to C, 1%). Fifty-three samples presented nucleotide insertion and deletion of C and A (CA) at position 514–523. Insertion of 1AC (3%) and 2AC (2%) were observed. Deletion of 1CA (53%) and 2CA (2%) at position 514–523 were revealed. The deletion of T at position 459 was observed. The haplotype diversity, random match probability, and discrimination power were calculated to be 0.7770, 0.2308, and 0.7692, respectively.     

Expanding the forensic German mitochondrial DNA control region database: genetic diversity as a function of sample size and microgeography

Mitochondrial DNA control region sequences were determined in 109 unrelated German Caucasoid individuals from north west Germany for both hypervariable regions 1 (HV1) and 2 (HV2) and 100 polymorphic nucleotide positions (nps) were found, 63 in HV1 and 37 in HV2. A total of 100 different mtDNA lineages was revealed, of which 7 were shared by 2 individuals and 1 by 3 individuals. The probability of drawing a HV1 sequence match within the north west Germans or within published sets of south Germans and west Austrians is similar (within a factor of 2) to drawing a sequence match between any two of these three population samples. Furthermore, HV1 sequences of 700 male inhabitants of one village in Lower Saxony were generated and these showed a nearly linear increase of the number of different haplotypes with increasing number of individuals, demonstrating that the commonly used haplotype diversity measure (Nei 1987) for population samples tends to underestimate mtDNA diversity in the actual population. Received: 14 January 1999 / Accepted: 15 February 1999     

Mitochondrial DNA control region sequences in Koreans: identification of useful variable sites and phylogenetic analysis for mtDNA data quality control

We have established a high-quality mtDNA control region sequence database for Koreans. To identify polymorphic sites and to determine their frequencies and haplotype frequencies, the complete mtDNA control region was sequenced in 593 Koreans, and major length variants of poly-cytosine tracts in HV2 and HV3 were determined in length heteroplasmic individuals by PCR analysis using fluorescence-labeled primers. Sequence comparison showed that 494 haplotypes defined by 285 variable sites were found when the major poly-cytosine tract genotypes were considered in distinguishing haplotypes, whereas 441 haplotypes were found when the poly-cytosine tracts were ignored. Statistical parameters indicated that analysis of partial mtDNA control region which encompasses the extended regions of HV1 and HV2, CA dinucleotide repeats in HV3 and nucleotide position 16497, 16519, 456, 489 and 499 (HV1ex+HV2ex+HV3CA+5SNPs) and the analysis of another partial mtDNA control region including extended regions of HV1 and HV2, HV3 region and nucleotide position 16497 and 16519 (HV1ex+HV2ex+HV3+2SNPs) can be used as efficient alternatives for the analysis of the entire mtDNA control region in Koreans. Also, we collated the basic informative SNPs, suggested the important mutation motifs for the assignment of East Asian haplogroups, and classified 592 Korean mtDNAs (99.8%) into various East Asian haplogroups or sub-haplogroups. Haplogroup-directed database comparisons confirmed the absence of any major systematic errors in our data, e.g., a mix-up of site designations, base shifts or mistypings. Electronic supplementary material Supplementary material is available for this article at and accessible for authorised users.     

Mitochondrial DNA D-loop hypervariable regions: Czech population data

In order to identify polymorphic sites and to find out their frequencies and the frequency of haplotypes, the complete D-loop of mitochondrial DNA (mtDNA) from 93 unrelated Czech Caucasians was sequenced. Sequence comparison showed that 85 haplotypes were found and of these 78 were unique, 6 were observed twice and 1 was observed three times. Genetic diversity (GD) was estimated at 0.999 and the probability of two randomly selected sequences matching (random match probability, RMP) at 1.2%. Additionally these calculations were carried out for hypervariable regions 1, 2 (HV1, HV2), for the area between HV1 and HV2 and for the area of the hypervariable region HV3. The average number of nucleotide differences (ANND) was established to be 10.2 for the complete D-loop. The majority of sequence variations were substitutions, particularly transitions. Deletions were found only in the region where HV3 is situated and insertions in the same place and in poly-C tracts between positions 303 and 315 in HV2. A high degree of length heteroplasmy was found especially in the regions of poly-C tracts between positions 16184 and 16193 in HV1 and between positions 303 and 315 in HV2. Position heteroplasmies were found in two cases.Electronic Supplementary Material Supplementary material is available in the online version of this article at http://dx.doi.org/10.1007/s00414-003-0407-2     

Investigation of mtDNA control region sequences in an Egyptian population sample

The sequences of mitochondrial DNA (mtDNA) control region were investigated in 101 unrelated individuals living in the northern region of Nile delta (Gharbia, N = 55 and Kafrelsheikh, N = 46). DNA was extracted from blood stained filter papers or buccal swabs. HV1, HV2 and HV3 were PCR amplified and sequenced; the resulted sequences were aligned and compared with revised Cambridge sequence (rCRS). The results revealed presence of total 93 different haplotypes, 86 of them are unique and 7 are shared haplotypes, the most common haplotype, was observed with a frequency, 2.97% of population sample. High mtDNA diversity was observed with genetic diversity and power of discrimination, 0.9982 and 0.9883, respectively. In this dataset the west Eurasian haplogroups predominated over the African haplogroups. The results would be useful for forensic examinations and human genetic studies.