Characterizing the morbid genome of ciliopathies

Background Ciliopathies are clinically diverse disorders of the primary cilium. Remarkable progress has been made in understanding the molecular basis of these genetically heterogeneous conditions; however, our knowledge of their morbid genome, pleiotropy, and variable expressivity remains incomplete. Results We applied genomic approaches on a large patient cohort of 371 affected individuals from 265 families, with phenotypes that span the entire ciliopathy spectrum. Likely causal mutations in previously described ciliopathy genes were identified in 85% (225/265) of the families, adding 32 novel alleles. Consistent with a fully penetrant model for these genes, we found no significant difference in their “mutation load” beyond the causal variants between our ciliopathy cohort and a control non-ciliopathy cohort. Genomic analysis of our cohort further identified mutations in a novel morbid gene TXNDC15, encoding a thiol isomerase, based on independent loss of function mutations in individuals with a consistent ciliopathy phenotype (Meckel-Gruber syndrome) and a functional effect of its deficiency on ciliary signaling. Our study also highlighted seven novel candidate genes (TRAPPC3, EXOC3L2, FAM98C, C17orf61, LRRCC1, NEK4, and CELSR2) some of which have established links to ciliogenesis. Finally, we show that the morbid genome of ciliopathies encompasses many founder mutations, the combined carrier frequency of which accounts for a high disease burden in the study population. Conclusions Our study increases our understanding of the morbid genome of ciliopathies. We also provide the strongest evidence, to date, in support of the classical Mendelian inheritance of Bardet-Biedl syndrome and other ciliopathies

Fetal cardiac evaluation, in particular application of the Tei or Myocardial Performance Index, to normal and pathological fetal hearts

This thesis aimed to evaluate the human fetal cardiac function using the modified myocardial performance index (Mod-MPI) modality in normal and pathological pregnancies. The previously developed Mod-MPI has been applied in normal pregnancies and in a wide range of patholog. In my initial attempt to evaluate the method I could not achieve similar results with which has been published before. In a large cohort of pregnant patients I modified the technique by altering machine settings and I could determine the best settings and apply them in my experiments. Furthermore I highlighted areas of clinical significance in the evaluation of Mod-MPI that have not been evaluated before. This included detailed exploration of the morphology of both right and left Mod-MPI Doppler waveforms and the significance of the valve click appearance on the measurement of the time intervals as well as the calculated ModMPI. I also evaluated the reproducibility of the Mod-MPI of the right ventricle and compare it for the first time with the left.I next developed the gestational age adjusted normal ranges in the Australian population of the right and left ModMPI based on three caliper positions defined in my established technique. I then evaluated the relationship between the right and left Mod-MPI (Delta Mod-MPI). I also evaluated the left Mod-MPI in a cohort of gestational diabetic others.Despite there being a large number of international groups undertaking research in this area, I could achieve novel results and accordingly future research should be directed towards universal agreement in the methodology of the Mod-MPI before further application of the technique in pathology

Use of the foetal myocardial performance index in monochorionic, diamniotic twin pregnancy: A prospective cohort and nested case-control study

Aims: Assess clinical utility of the foetal Myocardial Performance Index (MPI) in evaluation and management of monochorionic, diamniotic twin (MCDA) pregnancies. Methods: Prospective cohort of (a) initially uncomplicated MCDA (b) Complicated MCDA, including twin–twin transfusion syndrome (TTTS), selective intrauterine growth restriction (sIUGR), and liquor and/or growth discordance (L/GD) not meeting TTTS or sIUGR criteria. TTTS and sIUGR were case-control matched. Routine Dopplers and MPI were taken and correlated to diagnosis and final outcome. Results: Twenty-six always uncomplicated pairs, 51 always complicated pairs, and seven uncomplicated to pathological pairs were included. TTTS recipient (n = 25) left and right MPI and intertwin difference (ITD) were significantly elevated, however, were already elevated in Stage I (n = 10), and did not predict progression or pregnancy outcome. sIUGR MPI (n = 11) did not differ significantly from control. Of 15-L/GD pairs, two that progressed to TTTS had significantly higher left and right MPI values in the future recipient (0.61 and 0.72) versus future sIUGR larger twins (0.48 and 0.51) or stable L/GD (0.47 and 0.52): p <.01 for all comparisons. Conclusions: In this cohort, MPI did not add substantial diagnostic/prognostic information to current routine evaluation in established TTTS or sIUGR though potentially differentiated L/GD cases progressing to TTTS. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group

Is there a measurable difference between the left and right modified myocardial performance indices, and does this change to reflect unilateral myocardial dysfunction in pathology?

Introduction: Fetal cardiac dysfunction may manifest itself unilaterally as right and left ventricles differing in design, function and load, measurable as differing in myocardial performance indices (MPIs). We wished to define this difference ('delta-MPI' or DMPI), present its normal range and pilot its use in pathological pregnancy. Material and Methods: Prospective cross-sectional study of 324 normal singleton fetuses (16-38 weeks of gestation). Left and right modified MPI (LMPI and RMPI) were performed during a single examination using the 'peak' valve click technique. Thirty-seven pathological singleton and monochorionic diamniotic twin pregnancies were compared as pilot data. Results: Modified MPIs (mean ± SD) were 0.45 ± 0.06 (LMPI) and 0.47 ± 0.09 (RMPI), being similar at 18 weeks' gestation with DMPI increasing slightly throughout pregnancy (0.02 ± 0.08). Both singleton intrauterine growth restriction (IUGR) and recipient twin-twin transfusion syndrome (TTTS) showed significantly elevated RMPI, LMPI and DMPI, most pronounced for DMPI (450 and 500% increase, respectively; p < 0.01). DMPI acquisition rates were 83.3% normal and 87.0% pathological. Discussion: We demonstrate for the first time differing intrafetal LMPI and RMPI in a large gestational cohort, with this difference increasing with gestational age. Pilot data confirm the potential for DMPI as a tool to assess unilateral myocardial function in singleton IUGR and recipient twins in TTTS, and further studies are under way to evaluate its clinical utility. © 2015 S. Karger AG, Basel

Additional file 3: of Characterizing the morbid genome of ciliopathies

Supplemental clinical data: clinical details for the affected cases with mutations in novel candidate genes. (DOCX 35 kb

Additional file 2: Table S3. of Characterizing the morbid genome of ciliopathies

Clinical and genomic data for all cases in the study. (XLSX 83 kb

Additional file 5: Table S4. of Characterizing the morbid genome of ciliopathies

Identification of TXNDC15 interacting proteins using tandem affinity purification (TAP). The list of 224 unique proteins is significantly enriched in known or predicted ciliary proteins. (XLSX 30 kb

Additional file 1: Figure S1. of Characterizing the morbid genome of ciliopathies

Bar graph showing the percentage of the main features for each distinct ciliopathy syndrome. (PPTX 70 kb

Additional file 8: Table S1. of Characterizing the morbid genome of ciliopathies

List of diagnostic criteria used to clinically classify each ciliopathy. (XLSX 10 kb