A Novel Candidate Gene for Predisposition of Hodgkin Lymphoma; Pregnan X Receptor (PXR)

Objective Hodgkin lymphoma (HL) is a lymphoproliferative malignancy of B-cell origin and one of the common tumors in adolescent and young adults. Less than one percent of HL patients have a family history and siblings of the affected individual may have an increased risk of developing the disease. HL risk is associated with immunodeficiency syndromes. Clustering of cases of HL within families may also suggest a genetic predisposition. In cases with familial clustering, recognition of genetic predisposition genes in the pathogenesis of HL may offer therapeutic benefits, and provide genetic counseling and surveillance for the family members for early diagnosis. We had previously reported CD70 signaling defect in an extended family with multiple consanguineous marriages and individuals affected with Hodgkin lymphoma and/or immune deficiency (J Clin Immunol.2020, 40(6):883-892). The aim of this study is to investigate for a cancer predisposition gene/condition in two siblings with HL, whose parents had a consanguineous marriage. Material and Methods A 10 year-old girl with progressive HL was referred for further evaluation and treatment. She had been diagnosed with stage IIIBs HL, nodular sclerosing subtype and had received chemotherapy (ABVD) where she was reported to have partial response, followed by progressive disease. The tumor was CD30 positive. At admission, the patient had a massive enlarged mediastinum due to conglomerate lymph nodes, nodules in the lung, lymph adenomegalies in the cervical, supraclavicular, axillary regions. She was treated with ifosfamide+mesna, etoposide, carboplatinum (ICE) and brentuximab and achieved a complete metabolic response in PET-CT evaluation after six courses. She is transferred to receive stem cell transplantation. Her 24 year-old sister was also diagnosed with early stage HL during pregnancy, had a healthy delivery, was treated with chemotherapy and was in remission. In this study, we performed exome sequencing of the index case (IV-7). The elder sister who was diagnosed with HL and the parents, whose informed consents were taken. There were five children in the family; two of the girls were (IV-7 and IV-11) diagnosed with HL, a boy (IV-8) with inflammatory skin findings, a sister (IV-9) and a cousin (IV-13) with suspected lymphoma, and a healthy girl (IV-10) (Figure 1). After quality control and alignment steps, variants were annotated using ANNOVAR, dbSNP, and ExAC. Variant evaluation was performed by in-house filtering steps based on MAF<0.1%, CADD score >10, SIFT, PolyPhen, MutationTaster, FATHMM scores. We also used Pediatric Cancer Variant Pathogenicity Information Exchange (PeCanPIE) tool for identification and classification of the variants. Results A germline homozygous missense gene variation (c.928 G>A, p.D310N, rs144833620) was identified on the ligand binding domain of the Pregnane X Receptor Gene (PXR or NR1I2) gene. Sanger sequencing confirmed the familial segregation; IV-7 and IV-11 HL cases were homozygous and parents (III-13 and III-14) were heterozygous. The index case did not have elevated EBV-DNA PCR levels. Index case had increased CD3, CD2 and CD8 and reduced CD4 levels. (Conclusion) The PXR encodes a member of the nuclear receptor (NR) superfamily and functions in the metabolism and elimination of xenobiotics and several commonly used drugs. Heterodimerization of PXR and RXR (functional partner) lead to conformational changes upon ligand binding, functions as the transcriptional regulator of PXR target genes including metabolizing enzymes, drug transporters, inflammation and cell cycle associated genes. Previously reported Pxr-/- animal model showed that mice lacking the steroid and xenobiotic receptor develop B cell lymphoma. However, there is no case of HL published linked to variation in PXR gene. Clustering of cases of HL within families, especially in families with consanguineous marriages should suggest a genetic predisposition. The PXR seems to be a novel candidate gene for predisposition of HL. Funding: This study was funded by Scientific Research Projects Coordination Unit of Istanbul University with a project number TDK-2020-37127. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Consanguineous Marriages in India: Prevalence and Determinants

Consanguineous marriage is the legal union of male and female of a common ancestor related by blood. The most common prevailing form of consanguineous marriages is between first cousins. Middle East Asian countries and southern states in India show high prevalence. A comparative analysis between the two rounds of National Family Health Survey 1 and 4 have shown a declining trend for the practice of consanguineous marriages. The highest percentage of consanguineous marriages is seen among the first cousins from both father’s and mother’s side, most commonly practice in the southern states of Andhra Pradesh, Telangana, Tamil Nadu, and Karnataka except Kerala. Importantly, the practice of consanguineous marriage is higher among the Muslims of North India and Hindus of Southern India, among the Other Backward Classes and the less educated population of the middle and richer wealth index. A significant relationship can be noticed among consanguineous marriages and socio-economic variables.

Gene Hunting Approaches through the Combination of Linkage Analysis with Whole-Exome Sequencing in Mendelian Diseases: From Darwin to the Present Day

<b><i>Background:</i></b> In the context of medical genetics, gene hunting is the process of identifying and functionally characterizing genes or genetic variations that contribute to disease phenotypes. In this review, we would like to summarize gene hunting process in terms of historical aspects from Darwin to now. For this purpose, different approaches and recent developments will be detailed. <b><i>Summary:</i></b> Linkage analysis and association studies are the most common methods in use for explaining the genetic background of hereditary diseases and disorders. Although linkage analysis is a relatively old approach, it is still a powerful method to detect disease-causing rare variants using family-based data, particularly for consanguineous marriages. As is known that, consanguineous marriages or endogamy poses a social problem in developing countries, however, this same condition also provides a unique opportunity for scientists to identify and characterize pathogenic variants. The rapid advancements in sequencing technologies and their parallel implementation together with linkage analyses now allow us to identify the candidate variants related to diseases in a relatively short time. Furthermore, we can now go one step further and functionally characterize the causative variant through in vitro and in vivo studies and unveil the variant-phenotype relationships on a molecular level more robustly. <b><i>Key Messages:</i></b> Herein, we suggest that the combined analysis of linkage and exome analysis is a powerful and precise tool to diagnose clinically rare and recessively inherited conditions.

P–584 Female parental consanguinity is associated with a reduced ovarian reserve: a large observational study including 2198 women from the Arabian Peninsula

Study question Is parental consanguinity associated with reduced ovarian reserve in women from the Arabian Peninsula? Summary answer: Women descending from consanguineous unions have a reduced ovarian reserve compared with daughters of non-consanguine couples. What is known already Consanguineous marriage is defined as marriage between second-degree cousins or closer, with high prevalence in the Arabian Peninsula societies. An increased incidence of autosomal recessive diseases has been described in consanguineous marriages compared with non-consanguineous marriages. Despite the known adverse genetic impact of consanguinity, most available studies focus on the fertility of the consanguine couple. Only few publications, including low number of women, evaluated the impact of consanguinity on the fertility of their offspring, suggesting that daughters of consanguine parents might have reduced fertility associated to reduced ovarian reserve. Study design, size, duration A retrospective large-scale observational study was performed including 2482 women from the Arabian Peninsula who had their serum AMH and AFC measured as part of their fertility assessment at ART Fertility Clinics (UAE and Oman), from May 2015 to November 2019. Participants/materials, setting, methods 2482 women from the Arabian Peninsula, aged 19–50 years, were assessed. Consanguinity was defined as women whose parents were first-degree or second-degree cousins. Ovarian reserve was evaluated by Antral Follicle Count (AFC) with transvaginal ultrasound and serum AMH, measured by Elecsys (Cobas, Roche®) for all participants. Women with adnexal surgery history or/and hormonal treatment within previous three months (n = 284) were excluded. Ethical approval was obtained from the Research Ethics Committee (REFA040). Main results and the role of chance After excluding women with previous adnexal surgeries, 2198 women were included for analysis. A total of 605 participants (27.53%) were descendants from consanguineous unions and 1593 (72.47%) reported non-consanguineous kinship of their parents. AMH and AFC (mean±SD) for the consanguineous group were 2.62±2.88 ng/mL and 12.78±9.73 antral follicles, respectively; and AMH and AFC (mean±SD) for the non-consanguineous group were 2.65±2.91 ng/mL and 13.07±9.39 antral follicles, respectively. Women from the consanguinity group were significantly younger (mean±SD: 33.74±6.64 years old) compared with the non-consanguinity group (mean±SD: 34.78±6.64 years old, p &lt; 0.0001). Both groups were similar in BMI (mean±SD: 28.63±5.46 versus 28.41±5.60 kg/m2, p=ns), years of infertility (mean±SD: 3.80±3.68 vs 4.04±3.79, p=ns), type of infertility (primary/secondary), dress code (Hijab/Niqab) and smoking status. As expected, AMH and AFC exhibit an age-dependent decline. To evaluate the differences on ovarian reserve between both groups, a multivariate analysis was performed including age, consanguinity and AMH/AFC. Women from the consanguine group showed significantly lower levels of serum AMH (R2=0.264, p = 0.036) and AFC (R2=0.286, p = 0.003) compared with non-consanguineous women, and the highest differences were found for women below 35 years of age (AMH p = 0.035; AFC p = 0.001). Limitations, reasons for caution Despite the large number of women included, the retrospective study design is a limitation. Results have to be treated with caution before translating into other populations, as these data are obtained from women native to the Arabian Peninsula, with high sociocultural/religious/ethnical similarities, which might differ to other consanguine populations. Wider implications of the findings: Female parental consanguinity is associated with reduced ovarian reserve in the studied population, that might contribute to infertility. Future studies should examine the genetic and epigenetic basis of the current findings. Comprehensive clinical evaluation should include extensive family history and subsequent counselling of the affected couples. Trial registration number Not applicable

Investigating the Characteristics of Intelligence Quotient in Individuals with Intellectual Disability in Rafsanjan, 2019

Background: Comprehensive and reliable information about intellectual disability (ID) and its association with environmental and demographic variables is scarce. Objectives: This study aimed to investigate the characteristics of intelligence quotient (IQ) in children with ID. Methods: In this descriptive cross-sectional study, all children with ID under the care of the welfare organization and special needs schools of the city of Rafsanjan were included in the study by census sampling (n = 207). After obtaining informed consent, parents completed a checklist including participants’ age, gender, birth month, birth season, and birth order, and also parents’ age and education level. Data were analyzed by one-way ANOVA and chi-square tests. Results: Out of 207 children, 107 (51.7%) were male, 100 (48.3%) were female, 36.2% were first-born, 14.5% were born in May, and 5.3% were born in March (the most-the least). The relationship of IQ to birth season and month was not significant (P > 0.05). Among the children, 39.6% were offspring of consanguineous marriages, but no significant relationship was observed between their IQ and consanguineous marriages (P > 0.05). The level of ID was correlated with parents’ age (P < 0.05). A significant relationship was also found between IQ and the number of offspring (P = 0.004). All cases of severe ID were seen in girls and a significant relationship was detected between IQ and gender (P = 0.0001). Conclusions: Individuals with ID have an IQ below 70. ID in children was correlated with the parents’ old age and low education level, but not with their birth season. However, given the higher prevalence of infectious diseases especially viral infections in cold months, it is only sensible to educate couples about how to protect the health of mother and fetus during these periods.

Changing Trends of Consanguineous Marriages in South India

Consanguineous marriage is still a preferred option in many societies of southern India. Therefore, this study addresses the state and district wise variation in consanguineous marriages and also attempts to find out the underlying factors of this practice in different marriage cohorts of South India. Drawing data from National Family Health Survey-4, the result revealed that there is a reduction in consanguineous marriages from 32.6% who married before 1985 to 23% during 2010–2014. About 13 districts in Tamil Nadu had the highest prevalence of consanguineous marriages, indicating that recent socio-demographic changes such as delays in age at marriages, lesser age gaps between partners, increase in the level of education, etc., did not explicitly affect the consanguineous marriages.

Identifying the causes of recurrent pregnancy loss in consanguineous couples using whole exome sequencing on the products of miscarriage with no chromosomal abnormalities

Recurrent miscarriages occur in about 5% of couples trying to conceive. In the past decade, the products of miscarriage have been studied using array comparative genomic hybridization (a-CGH). Within the last decade, an association has been proposed between miscarriages and single or multigenic changes, introducing the possibility of detecting other underlying genetic factors by whole exome sequencing (WES). We performed a-CGH on the products of miscarriage from 1625 Iranian women in consanguineous or non-consanguineous marriages. WES was carried out on DNA extracted from the products of miscarriage from 20 Iranian women in consanguineous marriages and with earlier normal genetic testing. Using a-CGH, a statistically significant difference was detected between the frequency of imbalances in related vs. unrelated couples (P < 0.001). WES positively identified relevant alterations in 11 genes in 65% of cases. In 45% of cases, we were able to classify these variants as pathogenic or likely pathogenic, according to the American College of Medical Genetics and Genomics guidelines, while in the remainder, the variants were classified as of unknown significance. To the best of our knowledge, our study is the first to employ WES on the products of miscarriage in consanguineous families with recurrent miscarriages regardless of the presence of fetal abnormalities. We propose that WES can be helpful in making a diagnosis of lethal disorders in consanguineous couples after prior genetic testing.

THE INSTITUTION OF ZOROASTRIAN MARRIAGE XWēDōDAH: THE PROBLEMS OF GENESIS AND THE QUESTIONS OF TYPOLOGY

This paper deals with the famous Zoroastrian marriage xwēdōdah. This form of marriage refers to the conjugal union of father and daughter, mother and son, brother and sister. Zoroastrianism of the Sassanid era made this institution a key element of religion, along with offering meal (mēzd) and seasonal holidays (gāhānbār). The question of whether this institution is a part of ancient Iranian legacy or has emerged later, is still controversial among the scholars. Careful development of xwēdōdah in the late Pahlavi works after the Arab conquest in the 9th century could have been the propagation of the priesthood who tried to protect Zoroastrian society against infiltration and destruction or sticking to archaic norms in an effort to preserve their religion in the face of extinction. The paper gives an overview of the most relevant theories about xwēdōdah. The genesis of this institution probably traces to the pre-Indo-European cultural substrate. Some modern scholars, looking for an explanation, pay attention to the works of anthropologists. The rejection of incest in all societies with exogamic regulation led to a certain taboo. This taboo is often due to the birth defects of children born out of consanguineous marriages. In the author’s opinion, the hypothesis of “ritual value” by A.R. Radcliffe-Brown seems to be the most appropriate to this case.