‘We thought she was a witch’: Gender, class and whiteness in the familial ‘memory archive’

‘We thought she was a witch’ uses my own ‘memory archive’ to give texture to the complex inheritance of gender, class and race that characterises the present. Drawing on interviews, archival data and fictionalisation, the article explores the role of gendered labour in securing dominant understandings of class progress. Starting from stories, my mother and I weave together of the history of 64 Chepstow Road, Newport (where her maternal family lived), I highlight the cost of historiography that does not pay attention to what is written out of family memory. The article draws on existing feminist memory work to flesh out an intersectional approach to the ‘memory archive’ we inherit and introduces the importance of an imaginative approach to the past.

Association of ABCA4 Gene Polymorphisms with Cleft Lip with or without Cleft Palate in the Polish Population

Background: Non-syndromic cleft lip with/without cleft palate (NSCL/P) is a common congenital condition with a complex aetiology reflecting multiple genetic and environmental factors. Single nucleotide polymorphisms (SNPs) in ABCA4 have been associated with NSCL/P in several studies, although there are some inconsistent results. This study aimed to evaluate whether two SNPs in ABCA4, namely rs4147811 and rs560426, are associated with NSCL/P occurrence in the Polish population. Methods: The study included 627 participants: 209 paediatric patients with NSCL/P and 418 healthy newborn controls. DNA was isolated from the saliva of NSCL/P patients and from umbilical cord blood in the controls. Genotyping of rs4147811 and rs560426 was performed using quantitative PCR. Results: The rs4147811 (AG genotype) SNP in ABCA4 was associated with a decreased risk of NSCL/P (odds ratio (OR) 0.57; 95% confidence interval (CI) 0.39–0.84; p = 0.004), whereas the rs560426 (GG genotype) SNP was associated with an increased risk of NSCL/P (OR 2.13; 95% CI 1.31–3.48; p = 0.002). Limitations: This study—based on the correlation between single genetic variants and the occurrence of different phenotypes—might have limited power in detecting relevant, complex inheritance patterns. ORs are often low to moderate when investigating the association of single genes with the risk of a complex trait. Another limitation was the small number of available NSCL/P samples. Conclusions: The results suggest that genetic variations in ABCA4 are important risk markers of NSCL/P in the Polish population. Further investigation in a larger study group is warranted.

Oligogenic combinations of rare variants influence specific phenotypes in complex disorders

ABSTRACTGenetic studies of complex disorders such as autism and intellectual disability (ID) are often based on enrichment of individual rare variants or their aggregate burden in affected individuals compared to controls. However, these studies overlook the influence of combinations of rare variants that may not be deleterious on their own due to statistical challenges resulting from rarity and combinatorial explosion when enumerating variant combinations, limiting our ability to study oligogenic basis for these disorders. We present a framework that combines the apriori algorithm and statistical inference to identify specific combinations of mutated genes associated with complex phenotypes. Our approach overcomes computational barriers and exhaustively evaluates variant combinations to identify non-additive relationships between simultaneously mutated genes. Using this approach, we analyzed 6,189 individuals with autism and identified 718 combinations significantly associated with ID, and carriers of these combinations showed lower IQ than expected in an independent cohort of 1,878 individuals. These combinations were enriched for nervous system genes such as NIN and NGF, showed complex inheritance patterns, and were depleted in unaffected siblings. We found that an affected individual can carry many oligogenic combinations, each contributing to the same phenotype or distinct phenotypes at varying effect sizes. We also used this framework to identify combinations associated with multiple comorbid phenotypes, including mutations of COL28A1 and MFSD2B for ID and schizophrenia and ABCA4, DNAH10 and MC1R for ID and anxiety/depression. Our framework identifies a key component of missing heritability and provides a novel paradigm to untangle the genetic architecture of complex disorders.SIGNIFICANCEWhile rare mutations in single genes or their collective burden partially explain the genetic basis for complex disorders, the role of specific combinations of rare variants is not completely understood. This is because combinations of rare variants are rarer and evaluating all possible combinations would result in a combinatorial explosion, creating difficulties for statistical and computational analysis. We developed a data mining approach that overcomes these limitations to precisely quantify the influence of combinations of two or more mutated genes on a specific clinical feature or multiple co-occurring features. Our framework provides a new paradigm for dissecting the genetic causes of complex disorders and provides an impetus for its utility in clinical diagnosis.

Breeding of Cav2.3 deficient mice reveals Mendelian inheritance in contrast to complex inheritance in Cav3.2 null mutant breeding

High voltage-activated Cav2.3 R-type Ca2+ channels and low voltage-activated Cav3.2 T-type Ca2+ channels were reported to be involved in numerous physiological and pathophysiological processes. Many of these findings are based on studies in Cav2.3 and Cav3.2 deficient mice. Recently, it has been proposed that inbreeding of Cav2.3 and Cav3.2 deficient mice exhibits significant deviation from Mendelian inheritance and might be an indication for potential prenatal lethality in these lines. In our study, we analyzed 926 offspring from Cav3.2 breedings and 1142 offspring from Cav2.3 breedings. Our results demonstrate that breeding of Cav2.3 deficient mice shows typical Mendelian inheritance and that there is no indication of prenatal lethality. In contrast, Cav3.2 breeding exhibits a complex inheritance pattern. It might be speculated that the differences in inheritance, particularly for Cav2.3 breeding, are related to other factors, such as genetic specificities of the mutant lines, compensatory mechanisms and altered sperm activity.

GWAS Hits for Bilateral Convergent Strabismus with Exophthalmos in Holstein Cattle Using Imputed Sequence Level Genotypes

Bilateral convergent strabismus with exophthalmos (BCSE) is a malformation of the eyes and is recognized as a mild but progressive disorder that affects cattle in the first two years of life. This most likely inherited disorder is rarely described in cattle resembling autosomal dominantly inherited forms of human progressive external ophthalmoplegia (PEO). In German Braunvieh cattle, two linked genome regions were found that could be responsible for the development and/or progression of BCSE. The goal of this study was to phenotypically characterize BCSE in Holstein cattle from Germany and Switzerland as well as to identify associated genome regions by GWAS. The clinicopathological phenotype of 52 BCSE-affected Holstein cattle was in accordance with the phenotype described in German Braunvieh cattle, but in addition, signs of degeneration and cellular infiltration in the eye muscles were found. By using imputed sequence level genotype data, three genome-wide significant GWAS hits were revealed on different chromosomes that were not detected by initial GWAS based on high density SNP array data highlighting the usefulness of this approach for mapping studies. The associated genome regions include the ABCC4 gene as well as markers adjacent to the NCOR2 and DNAJC3 genes all illustrating possible functional candidate genes. Our results challenge a monogenic mode of inheritance and indicate a more complex inheritance of BCSE in Holstein cattle. Furthermore, in comparison to previous results from German Braunvieh cattle, it illustrates an obvious genetic heterogeneity causing BSCE in cattle. Subsequent whole genome sequencing (WGS)-based analyses might elucidate pathogenic variants in the future.

GWAS for autoimmune Addison’s disease identifies multiple risk loci and highlights AIRE in disease susceptibility

Autoimmune Addison’s disease (AAD) is characterized by the autoimmune destruction of the adrenal cortex. Low prevalence and complex inheritance have long hindered successful genetic studies. We here report the first genome-wide association study on AAD, which identifies nine independent risk loci (P < 5 × 10−8). In addition to loci implicated in lymphocyte function and development shared with other autoimmune diseases such as HLA, BACH2, PTPN22 and CTLA4, we associate two protein-coding alterations in Autoimmune Regulator (AIRE) with AAD. The strongest, p.R471C (rs74203920, OR = 3.4 (2.7–4.3), P = 9.0 × 10−25) introduces an additional cysteine residue in the zinc-finger motif of the second PHD domain of the AIRE protein. This unbiased elucidation of the genetic contribution to development of AAD points to the importance of central immunological tolerance, and explains 35–41% of heritability (h2).

Brugada-like electrocardiogram pattern in a young man taking a proton-pump inhibitor

The Brugada syndrome (BrS) is an electrical heart disease with complex inheritance (some cases with SCN5A mutations), characterized by specific electrocardiogram (ECG) markers and high risk of associated lethal ventricular arrhythmias [1]. The ECG signature of BrS consists of right precordial ST-segment elevation (≥2 mm) followed by negative T waves [1]. It sometimes includes the findings of right bundle branch block (RBBB). In certain cases, the typical ECG pattern is present intermittently which creates a potential problem for reaching the diagnosis of BrS. Another problem in diagnosing BrS is the presence of so-called Brugada phenocopies (BrPs), i.e. an acquired Brugada-like ECG pattern that are visually identical and indistinguishable from true BrS [2]. This ECG pattern can be caused by other conditions including ischemia of the ventricular septum and/or right ventricle or by taking certain medications [2]. Proton-pump inhibitors (PPIs) are widely prescribed, often for prolonged use, and have been associated with electrolyte disturbances and cardiac arrhythmias [3,4]. We hereby present for the first time the case of a patient with an ECG suggestive of BrS while taking PPI; but no other medication known to cause BrS. The BrS ECG pattern disappeared a few months after stopping the medication.

Evidence for non-Mendelian inheritance in spastic paraplegia 7

Hereditary spastic paraplegia is a group of rare motor neuron diseases considered to be inherited in a classical monogenic Mendelian manner. Although the typical inheritance of spastic paraplegia type 7 is autosomal recessive, several reports have suggested that SPG7 variants may also cause autosomal dominant HSP. We aimed to conduct an exome-wide genetic analysis on a large Canadian cohort of hereditary spastic paraplegia patients and controls to examine the association of SPG7 and hereditary spastic paraplegia. In total, 585 hereditary spastic paraplegia patients from 372 families and 1,175 controls, including 580 unrelated individuals, were analyzed for the presence of SPG7 variants. Whole exome sequencing was performed on 400 hereditary spastic paraplegia patients (291 index cases) and all 1,175 controls. After excluding 38 biallelic hereditary spastic paraplegia type 7 patients, the frequency of heterozygous pathogenic/likely pathogenic SPG7 variant carriers (4.8%) among hereditary spastic paraplegia unrelated index cases who underwent WES, was significantly higher than among unrelated controls (1.7%; OR=2.88, 95%CI=1.24-6.66, p=0.009). The heterozygous SPG7 p.(Ala510Val) variant was found in 3.7% of index cases vs. 0.85% in unrelated controls (OR=4.42, 95%CI=1.49-13.07, p=0.005). We identified four heterozygous SPG7 variant carriers with an additional pathogenic variant in genes known to cause hereditary spastic paraplegia, compared to zero in controls (OR=19.58, 95%CI=1.05-365.13, p=0.0031; Fisher Exact test with Haldane-Anscombe correction), indicating potential digenic inheritance. We further identified four families with heterozygous variants in SPG7 and SPG7-interacting genes (CACNA1A, AFG3L2 and MORC2). Out of these, there is especially compelling evidence for epistasis between SPG7 and AFG3L2. The p.(Ile705Thr) variant in AFG3L2 is located at the interface between hexamer subunits, in a hotspot of mutations associated with spinocerebellar ataxia type 28 that affect its proteolytic function. Our results provide evidence for complex inheritance in SPG7-associated hereditary spastic paraplegia, which may include recessive and possibly dominant and digenic/epistasis forms of inheritance.