Syndrome Carriers Research Articles

How does genetic risk information for Lynch syndrome translate to risk management behaviours?

BackgroundThere is limited research on why some individuals who have undergone predictive genetic testing for Lynch syndrome do not adhere to screening recommendations. This study aimed to explore qualitatively how Lynch syndrome non-carriers and carriers translate genetic risk information and advice to decisions about risk managment behaviours in the Australian healthcare system.MethodsParticipants of the Australasian Colorectal Cancer Family Registry who had undergone predictive genetic testing for Lynch syndrome were interviewed on their risk management behaviours. Transcripts were analysed thematically using a comparative coding analysis.ResultsThirty-three people were interviewed. Of the non-carriers (n = 16), 2 reported having apparently unnecessary colonoscopies, and 6 were unsure about what population-based colorectal cancer screening entails. Of the carriers (n = 17), 2 reported they had not had regular colonoscopies, and spoke about their discomfort with the screening process and a lack of faith in the procedure’s ability to reduce their risk of developing colorectal cancer. Of the female carriers (n = 9), 2 could not recall being informed about the associated risk of gynaecological cancers.ConclusionNon-carriers and female carriers of Lynch syndrome could benefit from further clarity and advice about appropriate risk management options. For those carriers who did not adhere to colonoscopy screening, a lack of faith in both genetic test results and screening were evident. It is essential that consistent advice is offered to both carriers and non-carriers of Lynch syndrome.

Incidence and Clinical Characteristics of Colonic and Extra Colonic Lynch Syndrome Manifestations in Uruguayan Mismatch Repair Carriers

Background: Colon cancer is a frequent diagnosis worldwide affecting both men and women. Lynch syndrome in an autosomal dominant inheritable condition, accountable for 5 to 7% of colon cancer, as well as other malignancies. Methodology: From a Uruguayan high risk cancer clinical setting, adult probands from 115 families, registered between 2015 and 2016, meeting Amsterdam I, II or Bethesda Revised guidelines, were tested for MMR genes and EPCAM. Results: Pathogenic Lynch Syndrome mutations were detected in 23.4% families. A total of 90 mutation carriers were diagnosed, from which information regarding molecular diagnosis, cancer diagnosis, cancer site, tumor staging, age at diagnosis and course of treatment was carefully analyzed. Cancer diagnosis before determination of carrier status was seen in 52.5% individuals; were 46.8% had more than one cancer diagnosis throughout lifetime, mostly colon cancer. The average age for colon cancer was 36.9 years old and 77% were stage II at diagnosis. Consequently, surgical treatment was the most frequent option, and partial colectomies the preferred surgical choice. Conclusions: Young age of onset and metachronous tumors are part of Lynch syndrome hallmark. How effective surveillance strategies are, are reflected on how well and timely we identify these young high risk adults. Treatment options are most frequently surgical ones, because of the stage these malignant tumors are found upon diagnosis. There is no unanimous consensus about the best surgical strategy for colon cancer Lynch syndrome carriers.

General practitioner attitudes towards prescribing aspirin to carriers of Lynch Syndrome: Findings from a national survey

A dose non-inferiority study comparing 100 mg, 300 mg and 600 mg of aspirin for cancer prevention among Lynch Syndrome carriers is underway (Colorectal Adenoma/Carcinoma Prevention Programme trial 3, CaPP3). To guide implementation of the findings, we investigated general practitioner (GP) attitudes towards aspirin prescribing for Lynch Syndrome carriers. We surveyed 1007 UK GPs (9.6% response rate). Using a within-subjects design, GPs read a statement on harms and benefits of aspirin and indicated their willingness to prescribe aspirin at three doses (100 mg, 300 mg, 600 mg). Approximately two-thirds (70.8%) of GPs had heard of Lynch Syndrome or its associated names, and among those 46.7% were aware of the cancer preventive effects of aspirin among carriers. Two-thirds (68.1%) of GPs reported feeling comfortable discussing harms and benefits of aspirin with a Lynch Syndrome patient. Willingness to prescribe was 91.3% at 100 mg, and declined to 81.8% at 300 mg and 62.3% at 600 mg (p < 0.001). In multivariable analyses, willingness to prescribe (600 mg) was higher among GPs ≥50 years (OR 1.46, 95% CI 1.03-2.07), more experienced GPs (OR 1.50, 95% CI 1.10-2.04), GPs who were aware of the cancer preventive effects of aspirin (OR 1.58, 95% CI 1.20-2.09), and those who reported seeing a Lynch Syndrome patient in practice (OR 1.44, 95% CI 1.01-2.05, p = 0.045). GPs report limited awareness of Lynch Syndrome and the preventive effects of aspirin among carriers. To ensure the optimal dose identified in the CaPP3 trial is readily available to patients, prescribing guidance and strategies to educate GPs should be developed.

Novel Blood Biomarkers Are Associated with White Matter Lesions in Fragile X- Associated Tremor/Ataxia Syndrome

Background: The need for accessible cellular biomarkers of neurodegeneration in carriers of the fragile X mental retardation 1 (FMR1) premutation (PM) alleles. Objective: To assess the mitochondrial status and respiration in blood lymphoblasts from PM carriers manifesting the fragile X-associated tremor/ataxia syndrome (FXTAS) and non-FXTAS carriers, and their relationship with the brain white matter lesions. Methods: Oxygen consumption rates (OCR) and ATP synthesis using a Seahorse XF^e24 Extracellular Flux Analyser, and steady-state parameters of mitochondrial function were assessed in cultured lymphoblasts from 16 PM males (including 11 FXTAS patients) and 9 matched controls. The regional white matter hyperintensity (WMH) scores were obtained from MRI. Results: Mitochondrial respiratory activity was significantly elevated in lymphoblasts from PM carriers compared with controls, with a 2- to 3-fold increase in basal and maximum OCR attributable to complex I activity, and ATP synthesis, accompanied by unaltered mitochondrial mass and membrane potential. The changes, which were more advanced in FXTAS patients, were significantly associated with the WMH scores in the supratentorial regions. Conclusion: The dramatic increase in mitochondrial activity in lymphoblasts from PM carriers may represent either the early stages of disease (specific alterations in short-lived blood cells) or an activation of the lymphocytes under pathological situations. These changes may provide early, convenient blood biomarkers of clinical involvements.

Antiphospholipid antibodies detected by line immunoassay differentiate among patients with antiphospholipid syndrome, with infections and asymptomatic carriers.

BackgroundAntiphospholipid antibodies (aPL) can be detected in asymptomatic carriers and infectious patients. The aim was to investigate whether a novel line immunoassay (LIA) differentiates between antiphospholipid syndrome (APS) and asymptomatic aPL+ carriers or patients with infectious diseases (infectious diseases controls (IDC)).MethodsSixty-one patients with APS (56 primary, 22/56 with obstetric events only, and 5 secondary), 146 controls including 24 aPL+ asymptomatic carriers and 73 IDC were tested on a novel hydrophobic solid phase coated with cardiolipin (CL), phosphatic acid, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidylserine, beta2-glycoprotein I (β2GPI), prothrombin, and annexin V. Samples were also tested by anti-CL and anti-β2GPI ELISAs and for lupus anticoagulant activity. Human monoclonal antibodies (humoAbs) against human β2GPI or PL alone were tested on the same LIA substrates in the absence or presence of human serum, purified human β2GPI or after CL-micelle absorption.ResultsComparison of LIA with the aPL-classification assays revealed good agreement for IgG/IgM aß2GPI and aCL. Anti-CL and anti-ß2GPI IgG/IgM reactivity assessed by LIA was significantly higher in patients with APS versus healthy controls and IDCs, as detected by ELISA. IgG binding to CL and ß2GPI in the LIA was significantly lower in aPL+ carriers and Venereal Disease Research Laboratory test (VDRL) + samples than in patients with APS. HumoAb against domain 1 recognized β2GPI bound to the LIA-matrix and in anionic phospholipid (PL) complexes. Absorption with CL micelles abolished the reactivity of a PL-specific humoAb but did not affect the binding of anti-β2GPI humoAbs.ConclusionsThe LIA and ELISA have good agreement in detecting aPL in APS, but the LIA differentiates patients with APS from infectious patients and asymptomatic carriers, likely through the exposure of domain 1.Electronic supplementary materialThe online version of this article (doi:10.1186/s13075-016-1018-x) contains supplementary material, which is available to authorized users.

Systematic immunohistochemical screening for Lynch syndrome in colorectal cancer: a single centre experience of 486 patients.

Germline mutations in DNA mismatch repair (MMR) genes MLH1, MSH2, MSH6 and PMS2 cause autosomal dominantly inherited Lynch syndrome. Lynch syndrome patients and their families benefit from life-saving intensive cancer surveillance. Approximately one in 30 colorectal cancers arises in the setting of Lynch syndrome. The aim of this study was to assess the detection rate of Lynch syndrome at our institution after introduction of systematic immunohistochemical screening for MMR deficiency in colorectal cancers from 2011 to 2015. Following the recommendations by the Evaluation of Genomic Applications in Practice and Prevention working group all colorectal cancers were immunohistochemically stained for the presence of MMR proteins MLH1, PMS2, MSH2 and MSH6, independent of clinical criteria. In the case of loss of MLH1, the somatic BRAF mutation V600E was assessed with molecular testing and/or immunohistochemistry. Clinical follow-up of potential Lynch syndrome carriers (patients with tumours showing loss of MLH1 expression with absence of BRAFV600E, loss of PMS2, MSH2 or MSH6) was evaluated. Of all patients (n = 486), loss of MMR protein expression was found in 73 (15.0%) tumours. Twenty-eight (6.0%) were classified as potential Lynch syndrome carriers. Of the genetically tested potential Lynch syndrome carriers (10 out of 28 patients), 40% were first diagnosed with Lynch syndrome. Implementation of systematic immunohistochemistry screening for Lynch syndrome showed that 6% of colorectal cancers were potentially Lynch-syndrome related. Tumour board protocols should systematically contain information on MMR status of all colorectal cancers and, in MMR deficient cases, include clear recommendations for genetic counselling for all potential Lynch syndrome patients.

23andMe: a new two-sided data-banking market model.

BackgroundSince 2006, the genetic testing company 23andMe has collected biological samples, self-reported information, and consent documents for biobanking and research from more than 1,000,000 individuals (90 % participating in research), through a direct-to-consumer (DTC) online genetic-testing service providing a genetic ancestry report and a genetic health report. However, on November 22, 2013, the Food and Drug Administration (FDA) halted the sale of genetic health testing, on the grounds that 23andMe was not acting in accordance with federal law, by selling tests of undemonstrated reliability as predictive tests for medical risk factors. Consumers could still obtain the genetic ancestry report, but they no longer had access to the genetic health report in the United States (US). However, this did not prevent the company from continuing its health research, with previously obtained and future samples, provided that consent had been obtained from the consumers concerned, or with health reports for individuals from other countries. Furthermore, 23andMe was granted FDA authorization on February 19, 2015, first to provide reports about Bloom syndrome carrier status, and, more recently, to provide consumers with “carrier status” information for 35 genes known (with high levels of confidence) to cause disease.DiscussionIn this Debate, we highlight the likelihood that the primary objective of the company was probably two-fold: promoting itself within the market for predictive testing for human genetic diseases and ancestry at a low cost to consumers, and establishing a high-value database/biobank for research (one of the largest biobanks of human deoxyribonucleic acid (DNA) and personal information).SummaryBy dint of this marketing approach, a two-sided market has been established between the consumer and the research laboratories, involving the establishment of a database/DNA biobank for scientific and financial gain. We describe here the profound ethical issues raised by this setup.

FMR1 gene mutations in patients with fragile X syndrome and obligate carriers: 30 years of experience in Chile.

Fragile X syndrome (FXS) is the most common form of inherited intellectual disability (ID) and co-morbid autism. It is caused by an amplification of the CGG repeat (>200), which is known as the full mutation, within the 5'UTR of the FMR1 gene. Expansions between 55-200 CGG repeats are termed premutation and are associated with a greater risk for fragile X-associated tremor/ataxia syndrome and fragile X-associated premature ovarian insufficiency. Intermediate alleles, also called the grey zone, include approximately 45-54 repeats and are considered borderline. Individuals with less than 45 repeats have a normal FMR1 gene. We report the occurrence of CGG expansions of the FMR1 gene in Chile among patients with ID and families with a known history of FXS. Here, we present a retrospective review conducted on 2321 cases (2202 probands and 119 relatives) referred for FXS diagnosis and cascade screening at the Institute of Nutrition and Food Technology (INTA), University of Chile. Samples were analysed using traditional cytogenetic methods and/or PCR. Southern blot was used to confirm the diagnosis. Overall frequency of FMR1 expansions observed among probands was 194 (8·8%), the average age of diagnosis was 8·8±5·4 years. Of 119 family members studied, 72 (60%) were diagnosed with a CGG expansion. Our results indicated that the prevalence of CGG expansions of the FMR1 gene among probands is relatively higher than other populations. The average age of diagnosis is also higher than reference values. PCR and Southern blot represent a reliable molecular technique in the diagnosis of FXS.

A Novel Multiplex Polymerase Chain Reaction Method for the Identification of Brachyspina Syndrome Carriers in Chinese Holstein Cattle

A Novel Multiplex Polymerase Chain Reaction Method for the Identification of Brachyspina Syndrome Carriers in Chinese Holstein Cattle Brachyspina syndrome (BS) is a monogenic autosomal recessive hereditary defect in Holstein dairy cattle. It is caused by a 3.3-kb deletion in the Fanconi anemia complementation group I (FANCI) gene on BTA21, which removes exons 25 to 27 and leads to a frame-shift and premature stop codon in exon 28. A consequence of BS is reduced reproduction efficiency and milk production in the dams due to loss of homozygous fetuses. In this study, we successfully developed a novel single-tube multiplex PCR assay to identify the recessive allele of BS with the bovine mitochondrial ATP synthase F0 subunit 8 (ATP8) genes as an internal positive control. We used this technique to detect BS alleles in a total of 63 Holstein bulls and 500 Chinese Holstein cows born between 2013 and 2015. Among them, 42 carriers were found (two sires and 40 cows). Combined with our previous study that assayed 206 Holstein bulls and 136 cows (born between 1996 and 2012) and identified 10 bull carriers and three cow carriers, the overall observed carrier frequency is 4.5% in bulls (269 assayed), and 6.8% in cows (636 assayed). Our method provides not only a reliable, economic, and practical diagnostic technique for BS carrier detection, but also promotes BS detection and monitoring system for the genetic improvement project of Chinese Holstein cattle.

Haemophilia A and cardiovascular morbidity in a female SHAM syndrome carrier due to skewed X chromosome inactivation

We have recently described a severe haemophilia A and moyamoya (SHAM) syndrome caused by Xq28 deletions encompassing F8 and the BRCC3 familial moyamoya gene. The phenotype includes haemophilia A, moyamoya angiopathy, dysmorphia and hypertension. The genetic analysis of the family of our SHAM patient demonstrated carrier state in proband's mother and sister.The patient's mother is apparently well, whereas his currently 18-years-old sister presents with mild haemophilia A, coarctation of the aorta, hypertension, and ventricular arrhythmia. We performed X chromosome inactivation assay based on HpaII methylation analysis of a polymorphic short tandem repeat (STR) in the X linked AR (androgen receptor) gene and used quantitative real-time RT PCR to measure the expression of genes from the deleted region in proband's family members. We found an extremely skewed X chromosome inactivation pattern in the female members of the family leading to preferential inactivation of the X chromosome without Xq28 deletion in patient's sister. We demonstrated differential expression of the genes from the deleted region in four members of the family, that tightly correlates with the clinical features.In conclusion, we show that the haematologic and cardiovascular morbidity and the discrepancy between patient's sister and mother despite the same genetic lesion are due to skewed X chromosome inactivation leading to clinically relevant differential expression of SHAM syndrome genes. This report highlights the role for BRCC3 in cardiovascular physiology and disease, and demonstrates that in some complex hereditary syndromes full diagnostics may require the examination of both genetic and epigenetic events.

Genotype-phenotype Correlation of the p.R1165C Mutation in the MYH9 Disorder: Report of a Japanese Pedigree.

MYH9 disorder is a rare autosomal dominant disease characterized by congenital thrombocytopenia with giant platelets and leukocyte inclusion bodies and is often associated with Alport-like symptoms, such as glomerulonephritis, sensorineural hearing loss, and cataracts. We report a Japanese pedigree wherein the MYH9 p.R1165C mutation was present in over 4 generations. Three individuals were misdiagnosed as Bernard-Soulier syndrome carriers. Among the 12 patients with abnormal hematological features, the proband's mother, aunt, and grandaunt presented with sensorineural hearing impairment, and the mother presented with presenile cataract, and nephritis. This case report confirms the previously established genotype-phenotype correlations of the MYH9 disorder that p.R1165C is associated with variable expression of nonhematological manifestations. Careful detection of leukocyte inclusion bodies in peripheral blood smears is necessary to prevent misdiagnosis.

Axonal neuropathy in female carriers of the fragile X premutation with fragile x-associated tremor ataxia syndrome.

In this study we examined whether females with the fragile X-associated tremor ataxia syndrome (FXTAS) and non-FXTAS premutation carriers have electrophysiological signs of underlying peripheral neuropathy. Nerve conduction studies (NCS) were performed on 19 women with FXTAS, 20 non-FXTAS carriers, and 26 age-matched controls. The results were compared with existing data on corresponding male carriers. Women with FXTAS and non-FXTAS carriers had reduced sensory nerve action potential amplitudes. Also, there was a strong trend for reduced compound muscle action potential amplitudes in women with FXTAS, but not in non-FXTAS carriers. No significant slowing of nerve conduction velocities, prolongation of F-wave latencies, or associations with molecular measures was observed. This study suggests an underlying axonal neuropathy in women with FXTAS. However, in comparison to men with FXTAS, the NCS abnormalities in women were less severe, possibly due to the effect of a normal X chromosome.

Advances in the study of Lynch syndrome in China.

Lynch syndrome, also known as hereditary nonpolyposis colorectal cancer, is an autosomal dominant genetic condition that has a high risk of colon cancer as well as other cancers due to inherited mutations in mismatch repair (MMR) genes. During the last decades, there have been great advances in research on Chinese Lynch syndrome. This review mainly focuses on the genetic basis, clinicopathologic features, diagnosis, intervention, chemoprevention, and surveillance of Lynch syndrome in China. In addition to frequently altered MMR genes, such as MLH1, MSH2, MSH6, and MLH3, other MMR-associated genes, such as those encoding human exonuclease 1, transforming growth factor β receptor 2, and alanine aminopeptidase, metastasis-associated protein 2, adenomatosis polyposis coli down-regulated 1, and hepatic and glial cell adhesion molecule have also been implicated in Chinese Lynch syndrome. Most Chinese researchers focused on the clinicopathologic features of Lynch syndrome, and it is noticeable that the most frequent extracolonic tumor in northeast China is lung cancer, which is different from other areas in China. The Chinese diagnostic criteria for Lynch syndrome have been established to identify gene mutation or methylation. With regard to chemoprevention, celecoxib may be effective to prevent polyps relapse in Lynch syndrome carriers. Additionally, a colonoscopy-based surveillance strategy for the prevention and early detection of neoplasms in Lynch-syndrome carriers has been proposed.

A rigorous approach for selection of optimal variant sets for carrier screening with demonstration of clinical utility.

Carrier screening for certain diseases is recommended by major medical and Ashkenazi Jewish (AJ) societies. Most carrier screening panels test only for common, ethnic-specific variants. However, with formerly isolated ethnic groups becoming increasingly intermixed, this approach is becoming inadequate. Our objective was to develop a rigorous process to curate all variants, for relevant genes, into a database and then apply stringent clinical validity classification criteria to each in order to retain only those with clear evidence for pathogenicity. The resulting variant set, in conjunction with next-generation DNA sequencing (NGS), then affords the capability for an ethnically diverse, comprehensive, highly specific carrier-screening assay. The clinical utility of our approach was demonstrated by screening a pan-ethnic population of 22,864 individuals for Bloom syndrome carrier status using a BLM variant panel comprised of 50 pathogenic variants. In addition to carriers of the common AJ founder variant, we identified 57 carriers of other pathogenic BLM variants. All variants reported had previously been curated and their clinical validity documented, or were of a type that met our stringent, preassigned validity criteria. Thus, it was possible to confidently report an increased number of Bloom’s syndrome carriers compared to traditional, ethnicity-based screening, while not reducing the specificity of the screening due to reporting variants of unknown clinical significance.

Electronic Health Records in the Genomics Era: Impact of Clinical Genomics

The human genome project has created a huge opportunity to move personalized genomic-based healthcare to the clinic [8-10]. This is greatly facilitated by the plummeting cost of DNA sequencing to about $1,000 a genome. Just this February, the US Federal Drug Administration approved a direct-to-consumer (DTC) genetic test for Bloom syndrome carrier status [11] by the company 23 and Me. The 1000 genome project [12] and more recently the 100,000 Genomes (Genomics England Project) have been generating a large amount of data on genetic variations, the Single Nucleotide Polymorphisms (SNPs) from individu-als around the globe. The Genome-Wide Association Studies (GWAS) are beginning to provide valuable clues to risk of disease development and phenotypic association for diverse diseases [13-19]. The clinical significance of the SNPs is incorporated in the Clinical Variations (ClinVar) database [20] from the National Center for Biotechnology Information (NCBI).Basic and translational researchers are well into the post genome era, but the current generations of physicians (with the exception of medical geneticists) are lagging far behind [21,22]. The Medical schools around the globe have been slow to incorporate modules on clinical genomics. Although use of genetic counselors has been the traditional medical approach, the field of genomics is highly complex and its datasets continuously evolving. Thus, a major gap exists between the advances in the genomics field and the physician interface with patients [23]. Furthermore, the EHR systems that are in wide use today offer little support for incorporation of genomics data. In a recent survey, only a small percentage of EHR specialists, primary care clinicians, medical geneticists, and genetic counselors surveyed (9%), felt that the EHR had an impact on genomics medicine [24]. There is a strong need for incorporating the genomics data into the EHR, if the advances in genetics are to help clinicians make the best-informed treatment decisions. In the past, genet-ic information was gathered, and patients counseled about the findings, only in families with a history of a particular disease or disorder. To begin to address this, the Electronic Medical Records and Genomics (eMERGE) Network, a National Human Genome Research Institute (NHGRI)-funded consortium was created. The eMERGE Network was tasked with developing methods and best practices for the utilization of the EHR as a tool for genomic research [25-27]. The network currently incor-porates nine geographically distinct groups around the US. The initial focus of the eMERGE phenotypes included cataract and High Density Lipoprotein (HDL), dementia, electrocardiograph-ic QRS duration, peripheral arterial disease, type 2 diabetes and hypothyroidism [27]. The eMERGE is now in its sixth year and second funding cycle (eMERGE II) and continues to make ad-vances in the field of genomics and health-care informatics. The first cycle of eMERGE had three major aims: (i) use EHR data for electronic phenotyping, (ii) conduct GWAS using the phenotypes and (iii) explore the ethical, legal, and social implications (ELSI) associated with EHR-based GWAS and wide-scale data sharing [25]. A Phenotype KnowledgeBase (PheKB) effort was created to develop phenotypic algorithms across the eMERGE network to facilitate mining the large-scale data.Integration of the genomics data into the EHR system faces considerable hurdles [28-30]. At the present time, no commercial EHR system is available that incorporates genomic data. Furthermore, the pharmacogenetic information, which could have a major impact in reducing adverse drug effects and efficacy, is still rarely used. This is despite strong evidence for clinical validity and utility for the pharmacogenetics use in the clinic [31-33].Other challenges for integration include the amount of the big data the GWAS studies generate (in terabytes), the rapidly expanding SNP variations dataset and the difficulty of establishing meaningful interpretations from these vast amounts of genetic data. The Version 1.0 of the eMERGE data encompassed more than 13 million SNPs from 42,000 samples [26]. In addition, there are a variety of EHR systems becoming available and a standard for handling the vast genomics information is lacking.

Cardiovascular risk in HIV/AIDS and Lipodystrophy Syndrome patients

Background: The treatment of people living with AIDS , known a highly active antiretroviral therapy (HAART), has increased considerably, and the disease has therefore acquired chronic features. Several changes have been observed, especially in cardiovascular disease risk. Objective: To assess cardiovascular risk in HIV/AIDS patients treated with HAART and compare this with Lipodystrophy Syndrome (LS) carriers. Methods: This is a descriptive cross-sectional study. 192 patients were recruited from a lipodystrophy outpatient centre, using Framingham risk scores. Results: After criteria inclusion/exclusion, the final sample consisted of 81 patients divided into two groups (HIV/AIDS - without lipodystrophy and HIV/LS - with lipodystrophy). The mean age of HIV/AIDS was 46.5 years, and of the HIV/LS patients was 52 years. In accordance with Framingham scores the cardiovascular risk in HIV/AIDS was 46.59% and 14.29% in HIV/LS. Conclusion: The risk of cardiovascular disease over 10 years is significantly higher in patients with lipodystrophy syndrome.

Extra Alleles in FMR1 Triple-Primed PCR: Artifact, Aneuploidy, or Somatic Mosaicism?

Triple-primed PCR assays have become the preferred fragile X syndrome testing method. Using a commercially available assay, we detected a reproducible extra peak(s) in 0.5% of 13,161 clinical samples. The objectives of this study were to determine the cause of these extra peaks; to identify whether these peaks represent an assay specific artifact, an underlying chromosome aneuploidy, or somatic mosaicism; and to ascertain their clinical relevance. The presence of an extra allele(s) was confirmed by a laboratory-developed PCR, with sequencing of the FMR1 5' UTR or Southern blot for some samples. The laboratory-developed procedure detected the extra allele(s) in 57 of 64 samples. Thus, we confirmed an extra peak, typically of lower abundance, in approximately 0.4% of all samples. Of these samples, 5 were from males and 52 were from heterozygous or homozygous females. Six patients likely had X chromosome aneuploidies. In 82.3% of samples, the extra allele had fewer repeats than the predominant allele(s). Additional alleles detected by FMR1 triple-primed PCR are not an assay-specific artifact and are likely due to X chromosome aneuploidies or somatic repeat instability. Additional normal alleles likely have no clinical significance for fragile X syndrome carrier or affected status. Extra alleles in individuals with normal karyotypes probably represent FMR1 somatic variation.

Mutation-free baby born from a mitochondrial encephalopathy, lactic acidosis and stroke-like syndrome carrier after blastocyst trophectoderm preimplantation genetic diagnosis

To investigate the applicability of preimplantation genetic diagnosis (PGD), we used trophectoderm (TE) biopsy to determine the mutation load in a 35-year-old female with mitochondrial encephalopathy, lactic acidosis and stroke-like syndrome (MELAS). Transfer of a mutation-free blastocyst gave birth to a healthy boy with undetectable mutation in any of the analyzed tissues. We found strong correlation among TE cells (r=0.90) within blastocysts and also between cytoplasmic fragments and TE (r=0.95). This is the first case of mutation-free baby born from a MELAS patient after TE biopsy and supports the applicability of blastocyst PGD for patients with mtDNA disorders to establish healthy offspring.

Ethnic effect on FMR1 carrier rate and AGG repeat interruptions among Ashkenazi women.

Fragile X syndrome, a common cause of intellectual disability, is usually caused by CGG trinucleotide expansion in the FMR1 gene. CGG repeat size correlates with expansion risk. Premutation alleles (55-200 repeats) may expand to full mutations in female meiosis. Interspersed AGG repeats decrease allele instability and expansion risk. The carrier rate and stability of FMR1 alleles were evaluated in large cohorts of Ashkenazi and non-Ashkenazi women. A total of 4,344 Ashkenazi and 4,985 non-Ashkenazi cases were analyzed using Southern blotting and polymerase chain reaction between 2004 and 2011. In addition, AGG interruptions were evaluated in 326 Ashkenazi and 298 non-Ashkenazi women who were recruited during 2011. Both groups had major peaks of 30 and 29 repeats. Ashkenazi women had a higher frequency of 30 repeats and a lower frequency of other peaks (P < 0.0001). A higher rate of premutations in the 55-59 repeats range (1:114 vs. 1:277) was detected among the Ashkenazi women. Loss of AGG interruptions (<2) was significantly less common among Ashkenazi women (9 vs. 19.5% for non-Ashkenazi women, P = 0.0002). Ashkenazi women have a high fragile X syndrome carrier rate and mostly lower-range premutations, and carry a low risk for expansion to a full mutation. Normal-sized alleles in Ashkenazi women have higher average number of AGG interruptions that may increase stability. These factors may decrease the risk for fragile X syndrome offspring among Ashkenazi women.

Characterization of Family History Profiles in a Large Series of Lynch Syndrome Carriers

INTRODUCTION: The purpose of this study was to characterize family history profiles of unaffected individuals diagnosed with Lynch syndrome in the absence of a known family mutation. METHODS: We queried our laboratory database for unaffected patients who were positive for Lynch syndrome genetic testing between September 2010 and May 2013. All individuals underwent full sequence and large rearrangement analysis of MLH1 and MSH2 and full sequence analysis of MSH6. Some patients also underwent full sequence and large rearrangement analysis of PMS2 and large rearrangement analysis of MSH6 and EPCAM. We then assessed family history profiles in 200 unaffected patients with genetically confirmed Lynch syndrome. RESULTS: Of the 200 patients, 162 female and 38 male Lynch syndrome carriers were identified. Mutations in MLH1 and MSH2 were the most common (30.0% and 32.5%, respectively). Eighteen patients lacked a first-degree or second-degree relative with colorectal cancer. Only 37.8% (73/193) of individuals had a first-degree or second-degree relative meeting Amsterdam II criteria, whereas 76.8% (149/194) of individuals had a first- or second-degree relative meeting Revised Bethesda criteria. The average PREMM1, 2, 6 score was 10.0% with 43.5% (87/200) falling below 5%. In this large cohort, 15.5% (31/200) had neither a first- or second-degree relative who met the Amsterdam II or Revised Bethesda criteria nor a PREMM1, 2, 6 score of 5% or greater. CONCLUSIONS: To improve detection of Lynch syndrome in the population, it is important to consider genetic testing in unaffected individuals even in the absence of a known family mutation.