PMP22 exon 4 deletion causes ER retention of PMP22 and a gain-of-function allele in CMT1E

OBJECTIVE: To determine whether predicted fork stalling and template switching (FoSTeS) during mitosis deletes exon 4 in peripheral myelin protein 22 KD (PMP22) and causes gain‐of‐function mutation associated with peripheral neuropathy in a family with Charcot–Marie–Tooth disease type 1E. METHODS: Two siblings previously reported to have genomic rearrangements predicted to involve exon 4 of PMP22 were evaluated clinically and by electrophysiology. Skin biopsies from the proband were studied by RT‐PCR to determine the effects of the exon 4 rearrangements on exon 4 mRNA expression in myelinating Schwann cells. Transient transfection studies with wild‐type and mutant PMP22 were performed in Cos7 and RT4 cells to determine the fate of the resultant mutant protein. RESULTS: Both affected siblings had a sensorimotor dysmyelinating neuropathy with severely slow nerve conduction velocities (<10 m/sec). RT‐PCR studies of Schwann cell RNA from one of the siblings demonstrated a complete in‐frame deletion of PMP22 exon 4 (PMP22Δ4). Transfection studies demonstrated that PMP22Δ4 protein is retained within the endoplasmic reticulum and not transported to the plasma membrane. CONCLUSIONS: Our results confirm that that FoSTeS‐mediated genomic rearrangement produced a deletion of exon 4 of PMP22, resulting in expression of both PMP22 mRNA and protein lacking this sequence. In addition, we provide experimental evidence for endoplasmic reticulum retention of the mutant protein suggesting a gain‐of‐function mutational mechanism consistent with the observed CMT1E in this family. PMP22Δ4 is another example of a mutated myelin protein that is misfolded and contributes to the pathogenesis of the neuropathy

Are we doing enough? Improved breastfeeding practices at 14 weeks but challenges of non-initiation and early cessation of breastfeeding remain: Findings of two consecutive cross-sectional surveys in KwaZulu-Natal, South Africa

Background KwaZulu-Natal (KZN) Initiative for breastfeeding support (KIBS) was a multipronged intervention to support the initiation and sustaining of breastfeeding, implemented between 2014 and 2017. We present results of two surveys conducted before and after KIBS implementation to assess changes in infant feeding practices in KZN over this time period. Methods Two cross-sectional surveys were conducted in primary health care clinics. Multistage stratified random sampling was used to select clinics and participants. Sample size was calculated to provide district estimates of 14-week exclusive breastfeeding (EBF) rates at baseline (KIBS1), and provincial estimates at endpoint (KIBS2). At KIBS1 the sample required was nine participating clinics in each of 11 districts (99 clinics) with 369 participants per district (N = 4059), and at KIBS2 was 30 clinics in KZN with 30 participants per clinic (N = 900). All caregivers aged ≥15 years attending the clinic with infants aged 13- < 16 weeks were eligible to participate. Data was collected using structured interviews on android devices. Multi-variable logistic regression was used to adjust odds ratios for differences between time points. Results At KIBS1 (May2014- March2015), 4172 interviews were conducted with carers, of whom 3659 (87.6%) were mothers. At KIBS2 (January–August 2017), 929 interviews were conducted which included 788 (84.8%) mothers. Among all carers the proportion exclusively breastfeeding was 44.6 and 50.5% (p = 0.1) at KIBS1 and KIBS2 respectively, but greater improvements in EBF were shown among mothers (49.9 vs 59.1: p = 0.02). There were reductions in mixed breastfeeding among all infants (23.2% vs 16.3%; p = 0.016). Although there was no change in the proportion of carers who reported not breastfeeding (31.9% vs 32.8%; p = 0.2), the duration of breastfeeding among mothers who had stopped breastfeeding was longer at KIBS2 compared to KIBS1 (p = 0.0015). Mothers who had returned to work or school were less likely to be breastfeeding (adjusted odds ratio [AOR] 3.76; 95% CI 3.1–4.6), as were HIV positive mothers (AOR 2.1; 95% CI 1.7–2.6). Conclusion Despite improvements to exclusive breastfeeding, failure to initiate and sustain breastfeeding is a challenge to achieving optimal breastfeeding practices. Interventions are required to address these challenges and support breastfeeding particularly among working mothers and HIV positive mothers.publishedVersio

Opposite trends in the consumption of manufactured and roll-your-own cigarettes in Spain (1991-2020)

Objective: the aim of this study is to describe trends in the consumption of manufactured and roll-your-own cigarettes between 1991 and 2012 in Spain, and to project these trends up to 2020. Methods: we estimated daily consumption per capita during 1991-2012 using data on sales of manufactured cigarettes (20-packs) and rolling tobacco (kg) from the Tobacco Market Commission, and using data of the Spanish adult population from the National Statistics Institute. We considered different weights (0.5, 0.8 and 1 g) to compute the number of rolled cigarettes per capita. We computed the annual per cent of change and assessed possible changes in trends using joinpoint regression, and projected the consumption up to 2020 using Bayesian methods. Results: daily consumption per capita of manufactured cigarettes decreased on average by 3.0% per year in 1991-2012, from 7.6 to 3.8 units, with three trend changes. However, daily consumption per capita of roll-your-own cigarettes increased on average by 14.1% per year, from 0.07 to 0.92 units of 0.5 g, with unchanged trends. Together, daily consumption per capita decreased between 2.9% and 2.5%, depending on the weight of the roll-your-own cigarettes. Projections up to 2020 indicate a decrease of manufactured cigarettes (1.75 units per capita) but an increase of roll-your-own cigarettes (1.25 units per capita). Conclusions: while the consumption per capita of manufactured cigarettes has decreased in the past years in Spain, the consumption of roll-your-own cigarettes has increased at an annual rate around 14% over the past years. Whereas a net decrease in cigarette consumption is expected in the future, use of roll-your-own cigarettes will continue to increase

Ataluren treatment of patients with nonsense mutation dystrophinopathy

Introduction: Dystrophinopathy is a rare, severe muscle disorder, and nonsense mutations are found in 13% of cases. Ataluren was developed to enable ribosomal readthrough of premature stop codons in nonsense mutation (nm) genetic disorders. Methods: Randomized, double-blind, placebo-controlled study; males ≥5 years with nm-dystrophinopathy received study drug orally 3 times daily, ataluren 10, 10, 20 mg/kg (N=57); ataluren 20, 20, 40 mg/kg (N=60); or placebo (N=57) for 48 weeks. The primary endpoint was change in 6-Minute Walk Distance (6MWD) at Week 48. Results: Ataluren was generally well tolerated. The primary endpoint favored ataluren 10, 10, 20 mg/kg versus placebo; the week 48 6MWD Δ=31.3 meters, post hoc P=0.056. Secondary endpoints (timed function tests) showed meaningful differences between ataluren 10, 10, 20 mg/kg, and placebo. Conclusions: As the first investigational new drug targeting the underlying cause of nm-dystrophinopathy, ataluren offers promise as a treatment for this orphan genetic disorder with high unmet medical need

Efficacy and Safety of Viltolarsen in Boys With Duchenne Muscular Dystrophy: Results From the Phase 2, Open-Label, 4-Year Extension Study

Background: Duchenne muscular dystrophy (DMD) is caused by DMD gene mutations, resulting in absence of functional dystrophin protein. Viltolarsen, an exon 53 skipping therapy, significantly increased dystrophin levels in patients with DMD. Presented here are completed study results of \u3e 4 years of functional outcomes in viltolarsen-treated patients compared to a historical control group (Cooperative International Neuromuscular Research Group Duchenne Natural History Study [CINRG DNHS]). Objective: To evaluate the efficacy and safety of viltolarsen for an additional 192 weeks in boys with DMD. Methods: This phase 2, open-label, 192-week long-term extension (LTE) study (NCT03167255) evaluated the efficacy and safety of viltolarsen in participants aged 4 to \u3c 10 years at baseline with DMD amenable to exon 53 skipping. All 16 participants from the initial 24-week study enrolled into this LTE. Timed function tests were compared to the CINRG DNHS group. All participants received glucocorticoid treatment. The primary efficacy outcome was time to stand from supine (TTSTAND). Secondary efficacy outcomes included additional timed function tests. Safety was continuously assessed. Results: For the primary efficacy outcome (TTSTAND), viltolarsen-treated patients showed stabilization of motor function over the first two years and significant slowing of disease progression over the following two years compared with the CINRG DNHS control group which declined. Viltolarsen was well tolerated, with most reported treatment-emergent adverse events being mild or moderate. No participants discontinued drug during the study. Conclusions: Based on the results of this 4-year LTE, viltolarsen can be an important treatment strategy for DMD patients amenable to exon 53 skipping