Longitudinal Changes in Epigenetic Age Acceleration in Aviremic Human Immunodeficiency Virus-Infected Recipients of Long-term Antiretroviral Treatment.

BACKGROUND: Human immunodeficiency virus (HIV) infection induces epigenetic age acceleration (EAA), but it remains unclear whether epigenetic aging continues to accelerate during successful antiretroviral therapy (ART) and prolonged virological suppression. METHODS: We longitudinally analyzed 63 long-term aviremic HIV-infected adults. Using blood DNA methylation patterns, we calculated EAA measures based on 3 epigenetic clocks (Horvath's clock, PhenoAge, and GrimAge). We recorded the emergence of serious AIDS-related and non-AIDS-related events throughout the study to assess its association with EAA. RESULTS: All participants were on stable ART and were virologically suppressed. After 4 years of follow-up, PhenoAge-EAA and GrimAge-EAA showed no differences, whereas Horvath-EAA slightly decreased (median difference, -0.53 years; P = .015). Longitudinal changes in EAA measures were independent of changes in CD4 cell counts, the ART regimen, or other HIV-related factors. Nineteen percent of participants experienced a serious clinical event during the study. Horvath-EAA was significantly higher at baseline in participants with clinical events (P = .027). After adjusting for confounders, we found a trend toward an association of higher levels of all EAA measures at baseline with serious clinical events. CONCLUSIONS: Epigenetic aging did not accelerate in long-term aviremic HIV-infected adults after 4 years of successful ART. EAA measures deserve further study as potential tools for predicting clinical events.

Coexistence of autosomal dominant polycystic kidney disease type 1 and hereditary renal hypouricemia type 2: A model of early-onset and fast cyst progression.

Autosomal dominant polycystic kidney disease (ADPKD) is a heterogeneous inherited disease characterized by renal and extrarenal manifestations with progressive fluid-filled cyst development leading to end-stage renal disease. The rate of disease progression in ADPKD exhibits high inter- and intrafamilial variability suggesting involvement of modifier genes and/or environmental factors. Renal hypouricemia (RHUC) is an inherited disorder characterized by impaired tubular uric acid transport with severe complications, such as acute kidney injury and chronic kidney disease (CKD). However, the two disorders have distinct and well-delineated genetic, biochemical, and clinical findings. Only a few cases of coexistence of ADPKD and RHUC (type 1) in a single individual have been reported. We report a family with two members: an ADPKD 24-year-old female which presented bilateral renal cysts in utero and hypouricemia since age 5, and her mother with isolated hypouricemia. Next-generation sequencing identified two mutations in two genes PKD1 and SLC2A9 in this patient and one isolated SLC2A9 mutation in her mother, showing RHUC type 2, associated to CKD. The coexistence of these two disorders provides evidence of SLC2A9 variant could act as a modifier change, with synergistic actions, that could promote cystogenesis and rapid ADPKD progression. This is the first case of coexistence of PKD1 and SLC2A9 mutations treated with tolvaptan.

International meeting on Wolf-Hirschhorn syndrome: Update on the nosology and new insights on the pathogenic mechanisms for seizures and growth delay.

"An International Meeting on Wolf-Hirschhorn Syndrome (WHS)" was held at The University Hospital La Paz in Madrid, Spain (October 13-14, 2017). One hundred and twenty-five people, including physicians, scientists and affected families, attended the meeting. Parent and patient advocates from the Spanish Association of WHS opened the meeting with a panel discussion to set the stage regarding their hopes and expectations for therapeutic advances. In keeping with the theme on therapeutic development, the sessions followed a progression from description of the phenotype and definition of therapeutic endpoints, to definition of genomic changes. These proceedings will review the major points of discussion.

GLI1 inactivation is associated with developmental phenotypes overlapping with Ellis-van Creveld syndrome.

GLI1, GLI2 and GLI3 form a family of transcription factors which regulate development by mediating the action of Hedgehog (Hh) morphogens. Accordingly, inactivating variants in GLI2 and GLI3 are found in several developmental disorders. In contrast, loss-of-function mutations in GLI1 have remained elusive, maintaining enigmatic the role of this gene in the human embryo. We describe eight patients from three independent families having biallelic truncating variants in GLI1 and developmental defects overlapping with Ellis-van Creveld syndrome (EvC), a disease caused by diminished Hh signaling. Two families had mutations in the last exon of the gene and a third family was identified with an N-terminal stop gain variant predicted to be degraded by the NMD-pathway. Analysis of fibroblasts from one of the patients with homozygous C-terminal truncation of GLI1 demonstrated that the corresponding mutant GLI1 protein is fabricated by patient cells and becomes upregulated in response to Hh signaling. However, the transcriptional activity of the truncated GLI1 factor was found to be severely impaired by cell culture and in vivo assays, indicating that the balance between GLI repressors and activators is altered in affected subjects. Consistent with this, reduced expression of the GLI target PTCH1 was observed in patient fibroblasts after chemical induction of the Hh pathway. We conclude that GLI1 inactivation is associated with a phenotypic spectrum extending from isolated postaxial polydactyly to an EvC-like condition.

Effect of HIV infection and antiretroviral therapy initiation on genome-wide DNA methylation patterns.

BACKGROUND: Previous epigenome-wide association studies have shown that HIV infection can disrupt the host DNA methylation landscape. However, it remains unclear how antiretroviral therapy (ART) affects the HIV-induced epigenetic modifications. METHODS: 184 individuals with HIV from the NEAT001/ANRS143 clinical trial (with pre-ART and post-ART samples [96 weeks of follow-up]) and 44 age-and-sex matched individuals without HIV were included. We compared genome-wide DNA methylation profiles in whole blood between groups adjusting for age, sex, batch effects, and DNA methylation-based estimates of leucocyte composition. FINDINGS: We identified 430 differentially methylated positions (DMPs) between HIV+ pre-ART individuals and HIV-uninfected controls. In participants with HIV, ART initiation modified the DNA methylation levels at 845 CpG positions and restored 49.3% of the changes found between HIV+ pre-ART and HIV-uninfected individuals. We only found 15 DMPs when comparing DNA methylation profiles between HIV+ post-ART individuals and participants without HIV. The Gene Ontology enrichment analysis of DMPs associated with untreated HIV infection revealed an enrichment in biological processes regulating the immune system and antiviral responses. In participants with untreated HIV infection, DNA methylation levels at top HIV-related DMPs were associated with CD4/CD8 ratios and viral loads. Changes in DNA methylation levels after ART initiation were weakly correlated with changes in CD4+ cell counts and the CD4/CD8 ratio. INTERPRETATION: Control of HIV viraemia after 96 weeks of ART initiation partly restores the host DNA methylation changes that occurred before antiretroviral treatment of HIV infection. FUNDING: NEAT-ID Foundation and Instituto de Salud Carlos III, co-funded by European Union.

Variability in Phelan-McDermid Syndrome in a Cohort of 210 Individuals.

Phelan-McDermid syndrome (PMS, OMIM# 606232) results from either different rearrangements at the distal region of the long arm of chromosome 22 (22q13.3) or pathogenic sequence variants in the SHANK3 gene. SHANK3 codes for a structural protein that plays a central role in the formation of the postsynaptic terminals and the maintenance of synaptic structures. Clinically, patients with PMS often present with global developmental delay, absent or severely delayed speech, neonatal hypotonia, minor dysmorphic features, and autism spectrum disorders (ASD), among other findings. Here, we describe a cohort of 210 patients with genetically confirmed PMS. We observed multiple variant types, including a significant number of small deletions (<0.5 Mb, 64/189) and SHANK3 sequence variants (21 cases). We also detected multiple types of rearrangements among microdeletion cases, including a significant number with post-zygotic mosaicism (9.0%, 17/189), ring chromosome 22 (10.6%, 20/189), unbalanced translocations (de novo or inherited, 6.4%), and additional rearrangements at 22q13 (6.3%, 12/189) as well as other copy number variations in other chromosomes, unrelated to 22q deletions (14.8%, 28/189). We compared the clinical and genetic characteristics among patients with different sizes of deletions and with SHANK3 variants. Our findings suggest that SHANK3 plays an important role in this syndrome but is probably not uniquely responsible for all the spectrum features in PMS. We emphasize that only an adequate combination of different molecular and cytogenetic approaches allows an accurate genetic diagnosis in PMS patients. Thus, a diagnostic algorithm is proposed.

Deep Phenotyping and Genetic Characterization of a Cohort of 70 Individuals With 5p Minus Syndrome.

Chromosome-5p minus syndrome (5p-Sd, OMIM #123450) formerly known as Cri du Chat syndrome results from the loss of genetic material at the distal region of the short arm of chromosome 5. It is a neurodevelopmental disorder of genetic cause. So far, about 400 patients have been reported worldwide. Individuals affected by this syndrome have large phenotypic heterogeneity. However, a specific phenotype has emerged including global developmental delay, microcephaly, delayed speech, some dysmorphic features, and a characteristic and monochromatic high-pitch voice, resembling a cat's cry. We here describe a cohort of 70 patients with clinical features of 5p- Sd characterized by means of deep phenotyping, SNP arrays, and other genetic approaches. Individuals have a great clinical and molecular heterogeneity, which can be partially explained by the existence of additional significant genomic rearrangements in around 39% of cases. Thus, our data showed significant statistical differences between subpopulations (simple 5p deletions versus 5p deletions plus additional rearrangements) of the cohort. We also determined significant "functional" differences between male and female individuals.

Epigenetic age acceleration changes 2 years after antiretroviral therapy initiation in adults with HIV: a substudy of the NEAT001/ANRS143 randomised trial.

BACKGROUND: DNA methylation-based estimators of biological age are reliable biomarkers of the ageing process. We aimed to investigate a range of epigenetic ageing biomarkers in a substudy of the NEAT001/ANRS143 clinical trial, which compared ritonavir-boosted darunavir with either raltegravir or tenofovir disoproxil fumarate and emtricitabine in antiretroviral therapy (ART)-naive adults. METHODS: We analysed frozen whole blood samples from 168 ART-naive participants with HIV from the NEAT001/ANRS143 trial, before ART initiation and after 2 years of ART (84 participants on ritonavir-boosted darunavir with raltegravir and 84 participants on ritonavir-boosted darunavir with tenofovir disoproxil fumarate and emtricitabine). We also included 44 participants without HIV with a similar age and sex distribution. We analysed DNA methylation. Epigenetic age estimators (Horvath's clock, Hannum's clock, GrimAge, and PhenoAge) and estimated leucocyte compositions were generated using Horvath's New Online Methylation Age Calculator and Houseman's method. We calculated epigenetic age acceleration measures for each estimator of epigenetic age. The NEAT001/ANRS143 trial is registered with ClinicalTrials.gov, NCT01066962. FINDINGS: Compared with the HIV-uninfected group, ART-naive participants with HIV showed higher epigenetic age acceleration (EAA) according to all EAA estimators (mean 2·5 years, 95% CI 1·89-3·22 for Horvath-EAA; 1·4 years, 0·74-1·99 for Hannum-EAA; 2·8 years, 1·97-3·68 for GrimAge-EAA; and 7·3 years, 6·40-8·13 for PhenoAge-EAA), with all differences being statistically significant except for Hannum-EAA (Horvath-EAA p=0·0008; Hannum-EAA p=0·059; GrimAge-EAA p=0·0021; and PhenoAge-EAA p<0·0001). Epigenetic ageing was more pronounced in participants who had CD4 counts less than 200 cells per µL (significant for PhenoAge and Hannum's clock, p=0·0015 and p=0·034, respectively) or viral loads over 100 000 copies per mL at baseline (significant for PhenoAge, p=0·017). After 2 years of ART, epigenetic age acceleration was reduced, although PhenoAge and GrimAge remained significantly higher in participants with HIV compared with participants without HIV (mean difference 3·69 years, 95% CI 1·77-5·61; p=0·0002 and 2·2 years, 0·47-3·99; p=0·013, respectively). There were no significant differences in the ART effect on epigenetic ageing between treatment regimens. At baseline, participants with HIV showed dysregulation of DNA methylation-based estimated leucocyte subsets towards more differentiated T-cell phenotypes and proinflammatory leucocytes, which was also partly restored with ART. INTERPRETATION: ART initiation partly reversed epigenetic ageing associated with untreated HIV infection. Further studies are needed to understand the long-term dynamics and clinical relevance of epigenetic ageing biomarkers in people with HIV. FUNDING: NEAT-ID Foundation.