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Reproductive genetic carrier screening (RGCS) provides people with information about their chance of having children with autosomal recessive or X-linked genetic conditions, enabling informed reproductive decision-making. RGCS is recommended to be offered to all couples during preconception or in early pregnancy. However, cost and a lack of awareness may prevent access. To address this, the Australian Government funded Mackenzie’s Mission—the Australian Reproductive Genetic Carrier Screening Project. Mackenzie’s Mission aims to assess the acceptability and feasibility of an easily accessible RGCS program, provided free of charge to the participant. In study Phase 1, implementation needs were mapped, and key study elements were developed. In Phase 2, RGCS is being offered by healthcare providers educated by the study team. Reproductive couples who provide consent are screened for over 1200 genes associated with >750 serious, childhood-onset genetic conditions. Those with an increased chance result are provided comprehensive genetic counseling support. Reproductive couples, recruiting healthcare providers, and study team members are also invited to complete surveys and/or interviews. In Phase 3, a mixed-methods analysis will be undertaken to assess the program outcomes, psychosocial implications and implementation considerations alongside an ongoing bioethical analysis and a health economic evaluation. Findings will inform the implementation of an ethically robust RGCS program.

Purpose: Developmental delay phenotypes have been associated with FMR1 premutation (PM: 55-200 CGG repeats) and "gray zone" (GZ: 45-54 CGG repeats) alleles. However, these associations have not been confirmed by larger studies to be useful in pediatric diagnostic or screening settings., Methods: This study determined the prevalence of PM and GZ alleles in two independent cohorts of 19,076 pediatric referrals to developmental delay diagnostic testing through Victorian Clinical Genetics Service (cohort 1: N = 10,235; cohort 2: N = 8841), compared with two independent general population cohorts (newborn screening N = 1997; carrier screening by the Victorian Clinical Genetics Service prepair program N = 14,249)., Results: PM and GZ prevalence rates were not significantly increased (p > 0.05) in either developmental delay cohort (male PM: 0.12-0.22%; female PM: 0.26-0.33%; male GZ: 0.68-0.69%; female GZ: 1.59-2.13-%) compared with general population cohorts (male PM: 0.20%; female PM: 0.27-0.82%; male GZ: 0.79%; female GZ: 1.43-2.51%). Furthermore, CGG size distributions were comparable across datasets, with each having a modal value of 29 or 30 and ~1/3 females and ~1/5 males having at least one allele with ≤26 CGG repeats., Conclusion: These data do not support the causative link between PM and GZ expansions and developmental-delay phenotypes in pediatric settings.

We report an unusual case of periodic fever associated with persistent splenomegaly in a 2-year-old boy. Febrile episodes occurred at regular 2 weekly intervals and each lasted for 1-2 days. Following resolution of the fever on each occasion, the patient developed neck stiffness of 1-2 days duration. The periodic febrile episodes, as well as the splenomegaly, spontaneously resolved 9 months after the onset of disease. Infectious and malignant causes were ruled out as far as possible. This patient's clinical features are unusual and do not match any known category of periodic fevers in childhood. We believe this case highlights the diagnostic challenges periodic fevers commonly represent.

As with other major autoimmune diseases, susceptibility to multiple sclerosis (MS) is believed to result from the complex interaction of a number of genes, each with modest effect. Extensive research of experimental autoimmune encephalomyelitis in mice and several direct MS studies have implicated NOS2A, which encodes the inducible form of nitric oxide synthase, and the genetic region encoding NOS2A, 17q11.2, has been identified in a number of genome wide screens as being potentially associated with MS. We investigated four single nucleotide polymorphisms in the proximal promoter region of NOS2A, in a case-control group of 100 Australian MS patients and 100 controls and in 203 MS patients and their unaffected parents. We found a trend toward excess transmission of the -277A allele (tag for the AGCC haplotype) to HLA-DRB1*1501-positive MS patients (P (uncorrected)=0.05). We initially discovered a trend toward over-representation of the AGCC haplotype in HLA-DRB1*1501-positive compared to HLA-DRB1*1501-negative MS patients in the case-control cohort. However, when combined with the probands from the transmission disequilibrium analysis, this trend was nullified. Nonetheless, despite the lack of significant evidence of association for the NOS2A promoter polymorphisms with MS, the gene remains an interesting candidate for MS susceptibility, particularly with regard to the HLA-DRB1*1501 haplotype.

CCL-L1 binds more potently to CCR5 than any other chemokine; it inhibits HIV-1 infection in vitro, and its gene occurs in variable copy numbers, some individuals failing to produce it. We analysed the frequency of the absence of CCL3-L1 in 268 Caucasian Australian HIV-1 patients and 260 uninfected individuals. A CCL-L1-negative genotype frequency of 2.3% was found in HIV-1 negative individuals. No association was found between the absence of CCL3-L1 and susceptibility to, or rate of progression of, HIV-1 infection.

We earlier found an association between anorexia nervosa (AN) restrictive subtype (AN-R) and an inserted sequence within the NETpPR, a polymorphic region located in the promoter of the solute carrier family 6 (neurotransmitter transporter, noradrenalin) member 2 (SLC6A2) gene. To further examine the noradrenergic system in AN-R we performed an association study with a functional polymorphism (MAOA-uVNTR) in the promoter of the monoamine oxidase A (MAOA) gene. Since monoamine oxidase A metabolises noradrenalin, a positive association with the MAOA gene would be biologically plausible. The transmission disequilibrium test and 95 trios/duos (AN-R females+biological parents) showed the main effect of the longer, more transcriptionally active form of the MAOA-uVNTR (MAOA-L) to be statistically non-significant (McNemar's chi(2)=1.4, df=1, P=0.238, odds ratio: 1.4, 95% CI 0.8-2.7). A case-control approach supported this finding. We then stratified the MAOA-uVNTR TDT data according to the (a) NETpPR genotype of the AN-R females, and (b) NETpPR allele transmitted from NETpPR-S4/L4 heterozygous mothers. In both cases, contingency table analysis revealed previously unreported gene-gene interaction between the MAOA and SLC6A2 genes (P=0.019 and 0.019, respectively). Receiving an MAOA-L allele more than doubles the risk for developing AN-R, conditional on an individual also being a NETpPR-L4 homozygote (stratum-specific odds ratio: 2.4, 95% CI 1.1-6.0). These results suggest important involvement of the noradrenergic system in the biological underpinnings of AN-R.

Weight-restored patients with anorexia nervosa (AN) respond favorably to the selective serotonin reuptake inhibitor fluoxetine, which justifies association studies of the serotonin transporter gene (SLC6A4, alias SERT) and AN. Case-control studies suggest that the least transcriptionally active allele of the SERT gene promoter polymorphism (5-HTTLPR) has an increased frequency in AN patients. However, this finding was not replicated with 55 trios (AN child+parents) and the transmission disequilibrium test (TDT). To clarify the role of the 5-HTTLPR in susceptibility to AN, we used the TDT and 106 Australian trios to provide 93% power to detect a genotypic relative risk (GRR) of 2.0. Our results were negative for this GRR (McNemar's chi(2)=0.01, df=1, p=0.921, odds ratio 1.0, 95% CI 0.7-1.5). Additionally, we found no association with AN females, AN subtype, age at onset, or minimum BMI. We then performed the first reported investigation of epistasis between the SERT gene and norepinephrine transporter gene (SLC6A2, alias NET) in AN, as an earlier study suggested that atypical AN responds to the dual serotonin-norepinephrine reuptake inhibitor venlafaxine. We observed no epistasis between the 5-HTTLPR and a polymorphism within the NET gene promoter polymorphic region (NETpPR) (chi(2)=0.48, df=1, p=0.490). Although 5-HTTLPR modulates serotonin reuptake by the serotonin transporter, our analyses provide no evidence that susceptibility to AN is modified by 5-HTTLPR alone, nor in concert with as yet undetermined functional effects of the NETpPR polymorphism.

We have investigated the interleukin-7 receptor (IL-7R) alpha-chain gene as a positional and functional candidate gene for susceptibility to multiple sclerosis (MS), in view of its chromosomal location on 5p14-p12, a region that has shown suggestive linkage in MS genome screens, and its role in T- and B-cell proliferation and reactivity. Amplification and DNA sequencing of the IL-7Ralpha gene in pooled and individual samples identified 13 single nucleotide polymorphisms (SNPs), 11 of which are novel, including three in the promoter region, three in exons encoding amino-acid changes (ACC(Thr)66ATC(Ile), ATC(Ile)244ACC(Thr), ATC(Ile)336GTC(Val)), four in introns and one in the 3' untranslated region. Four IL-7R haplotypes were identified for nine SNPs, showing linkage disequilibrium across the gene, and allowing haplotype frequency determination from just three of the nine SNPs. Genotyping of the -504 polymorphism in 101 MS and 90 controls showed a suggestive (P=0.1) association of the T allele with MS; however, this was not supported by transmission disequilibrium testing in 186 MS trio families (P=0.8). There were trends towards an increase of the GTG+ haplotype (odds ratio=1.45), and under-representation of the TTA+ haplotype (OR=0.65) in DRB1*1501-positive MS cases, suggesting that larger sample sizes and comparison in more defined MS patient groups may support an association with the IL-7R gene. These polymorphisms would also be useful for studying genetic associations with other immunologic diseases.

The role of genetic factors in determining susceptibility to multiple sclerosis is well established but, despite the global distribution of the disease, systematic efforts to locate susceptibility genes have concentrated exclusively on populations from the Northern Hemisphere. We performed a genome wide screen of linkage in the Australian population using a panel of 397 microsatellite markers in 54 affected sibling-pairs. Multipoint linkage analysis revealed four regions of suggestive linkage (on chromosomes 2p13, 4q26-28, 6q26 and Xp11) and 18 additional regions of potential linkage (at 1q43-44, 3q13-24, 4q24, 4q31-34, 5q11-13, 6q27, 7q33-35, 8p23-21, 9q21, 13q31-32, 16p13, 16p11, 16q23-24, 17p13, 18p11, 20p12-11, Xp21-11 and Xq23-28). Our results contribute to the available data adding new provisional regions of linkage as well as increasing support for areas previously implicated in genetic susceptibility to multiple sclerosis.

Objectives: There have been many studies reporting restricted patterns of T cell receptor usage in established multiple sclerosis and these have led to clinical trials of immunomodulation directed at deleting clonal T cell populations. The present study aims to test the hypothesis that highly restricted T cell populations are also present in the CSF in the earliest clinical stages of acute demyelinating disease of the CNS., Methods: T cell receptor Vbeta (TCRBV) gene expression was studied in CSF and blood in nine patients with acute optic neuritis within 7 days of onset of symptoms, six patients with an acute relapse of multiple sclerosis, and 13 control subjects. RNA was extracted and cDNA synthesised from unstimulated CSF and blood lymphocytes, and TCRBV gene segments were amplified from the cDNA by polymerase chain reaction (PCR) using 21 family specific primers. PCR products were separated by polyacrylamide gel electrophoresis and detected via a labelled oligonucleotide probe. A semiquantitative analysis of band intensity was performed by laser densitometry., Results: TCRBV mRNA was detected in the CSF of eight of nine patients with optic neuritis, six of six patients with multiple sclerosis, and five of 13 controls, and was closely correlated with the presence of oligoclonal IgG. Usage of a single TCRBV family was demonstrated in two of nine patients with optic neuritis and two of six patients with multiple sclerosis. The number of TCRBV families expressed in the other patients ranged between 5 and 15 (optic neuritis) and 4 and 17 (multiple sclerosis)., Conclusions: There is a relative lack of restriction of TCRBV usage by CSF lymphocytes in the very earliest stages (<7 days) of acute optic neuritis. This may imply either that multiple sclerosis is not a monoclonal disease even at onset, or that the autoimmune response has widened before the disease becomes clinically evident. This may have important consequences for the design of immune therapies in multiple sclerosis. Further studies are required to determine whether the CSF T cell repertoire at presentation has prognostic importance. Longitudinal studies are required to follow the CSF T cell repertoire from the time of presentation and to determine whether it may have prognostic significance.

Background: The beta-chemokine receptor CCR-5 is used as a coreceptor by macrophage-tropic strains of HIV-1 to gain entry into CD4+ cells., Objective: To determine the effect of a common 32 base-pair deletion mutation in the CCR-5 gene (CCR-5 delta 32) on progression of HIV infection to AIDS, and to assess the level of heterozygosity for this mutation in a well-defined group of long-term non-progressors (LTNP)., Participants: Sixty-four HIV-1-infected LTNP (CD4+ T lymphocyte count > 500 x 10(6)/l after 8 years) were compared with 95 individuals infected within a similar period (1983-1986) but who had rapidly progressed to AIDS and death, and with a further 120 HIV-positive individuals with CD4+ counts < 500 x 10(6)/l., Methods: The presence of the CCR-5 delta 32 mutation was assessed using polymerase chain reaction with primers spanning the 32 base-pair deletion. CD4+ and CD8+ counts, plasma HIV-1 RNA, p24 antigen and beta 2-microglobulin levels in LTNP carrying the CCR-5 delta 32 mutation were compared with LTNP lacking the mutation., Results: A marked increase in the frequency of CCR-5 delta 32 heterozygosity was found among LTNP (35.9%) compared with rapid progressors (12.6%; P = 0.0005) and patients selected on the basis of a CD4+ T-cell count < 500 x 10(6)/l (12.5%; P = 0.0004). LTNP heterozygous for CCR-5 delta 32 had a significantly higher CD8+ T-cell count than those without the mutation (1218 versus 972 x 10(6)/l; P = 0.044). No significant correlation was observed between heterozygosity and CD4 count, viral load, p24 antigen or beta 2-microglobulin within the LTNP group., Conclusions: This study provides the strongest evidence to date for the importance of a single copy of the CCR-5 delta 32 mutation in long-term non-progression of HIV infection, which may involve, in part, CD8+ T lymphocytes.