Identification of a novel founder variant in DNAI2 cause primary ciliary dyskinesia in five consanguineous families derived from a single tribe descendant of Arabian Peninsula.

Introduction: Primary ciliary dyskinesia (PCD) is caused by dysfunction of motile cilia resulting in insufficient mucociliary clearance of the lungs. The overall aim of this study is to identify disease causing genetic variants for PCD patients in the Kuwaiti population. Methods: A cohort of multiple consanguineous PCD families was identified from Kuwaiti patients and genomic DNA from the family members was analysed for variant screening. Transmission electron microscopy (TEM) and immunofluorescent (IF) analyses were performed on nasal brushings to detect specific structural abnormalities within ciliated cells. Results: All the patients inherited the same founder variant in DNAI2 and exhibited PCD symptoms. TEM analysis demonstrated lack of outer dynein arms (ODA) in all analysed samples. IF analysis confirmed absence of DNAI1, DNAI2, and DNAH5 from the ciliary axoneme. Whole exome sequencing, autozygosity mapping and segregation analysis confirmed that seven patients carry the same homozygous missense variant (DNAI2:c.740G>A; p.Arg247Gln; rs755060592). Conclusion: DNAI2:c.740G>A is the founder variant causing PCD in patients belonging to a particular Arabian tribe which practices consanguineous marriages.

Outcomes of Long-Term Noninvasive Ventilation Use in Children with Neuromuscular Disease: Systematic Review and Meta-Analysis.

Objectives: To determine whether children with neuromuscular disorders using long-term noninvasive ventilation (NIV), continuous or bilevel positive airway pressure, have improved health outcomes compared with alternative treatment strategies. Data Sources: This systematic review is an extension of a scoping review. The search strategy used Medical Subject Headings and free-text terms for "child" and "noninvasive ventilation." Studies of humans from 1990 onward were searched in MEDLINE (Ovid), Embase (Ovid), CINAHL (Ebsco), Cochrane Library (Wiley), and PubMed. The results were reviewed for articles reporting on neuromuscular disorders and health outcomes including mortality, hospitalization, quality of life, lung function, sleep study parameters, and healthcare costs. Data Extraction: Extracted data included study design, study duration, sample size, age, type of NIV, follow-up period, primary disease, and primary and secondary outcome measures. Studies were grouped by primary disease into three groups: spinal muscular atrophy, Duchenne muscular dystrophy, and other/multiple neuromuscular diseases. Data Synthesis: A total of 50 articles including 1,412 children across 36 different neuromuscular disorders are included in the review. Mortality is lower for children using long-term NIV compared with supportive care across all neuromuscular disease types. Overall, mortality does not differ when comparing the use of NIV with invasive mechanical ventilation, though heterogeneity suggests that mortality with NIV is higher for spinal muscular atrophy type 1 and lower for other/multiple neuromuscular diseases. The impact of long-term NIV on hospitalization rate differed by neuromuscular disease type with lower rates compared with supportive care but higher rates compared with supportive care use for spinal muscular atrophy type 1, and lower rates compared with before NIV for other/multiple neuromuscular diseases. Overall, lung function was unaltered and sleep study parameters were improved from baseline by long-term NIV use. There are few data to assess the impact of long-term NIV use on quality of life and healthcare costs. Conclusions: Long-term NIV for children provides benefit for mortality, hospitalizations, and sleep study parameters for some sub-groups of children with neuromuscular disorders. High risk of bias and low study quality preclude strong conclusions.

Long-term Non-Invasive Ventilation in Infants: A Systematic Review and Meta-Analysis.

BACKGROUND: The use of long-term non-invasive ventilation (NIV) to treat sleep and breathing disorders in children has increased substantially in the last decade; however, less data exist about its use in infants. Given that infants have distinct sleep and breathing patterns when compared to older children, the outcomes of infants on long-term NIV may differ as well. The aim of this study is to systematically review the use and outcomes of long-term NIV in infants. METHODS: Ovid Medline, Ovid Embase, CINAHL (via EbscoHOST), PubMed, and Wiley Cochrane Library were systematically searched from January 1990 to July 2017. Studies on infants using long-term NIV outside of an acute care setting were included. Data were extracted on study design, population characteristics, and NIV outcomes. RESULTS: A total of 327 studies were full-text reviewed, with final inclusion of 60. Studies were distributed across airway (40%), neuromuscular (28%), central nervous system (10%), cardio-respiratory (2%), and multiple (20%) disease categories. Of the 18 airway studies reporting on NIV outcomes, 13 (72%) reported improvements in respiratory parameters. Of the 12 neuromuscular studies exclusively on spinal muscular atrophy type 1 (SMA1), six (50%) reported decreased hospitalizations and nine (75%) reported on mortality outcomes. Risk of bias was moderate to serious, and quality of the evidence was low to very low for all studies. Most studies had an observational design with no control group, limiting the potential for a meta-analysis. CONCLUSION: The outcomes reported in studies differed by the disease category being studied. Studies on airway conditions showed improvements in respiratory parameters for infants using NIV. Studies on neuromuscular disorder, which were almost exclusively on SMA1, reported decreased hospitalizations and prolonged survival. Overall, it appears that NIV is an effective long-term therapy for infants. However, the high risk of bias and low quality of the available evidence limited strong conclusions.