2020 design and methods of the Population Assessment of Tobacco and Health (PATH) study during the COVID-19 pandemic.

The Population Assessment of Tobacco and Health (PATH) Study is a nationally representative, longitudinal study of the US population on tobacco use and its effects on health, collecting data annually since 2013. The COVID-19 pandemic interrupted in-person survey data collections around the world. In the USA, this included a PATH Study data collection focused on youth (13-17) and young adults (18-19) as well as other US surveys on tobacco use. Given that it was necessary to pause data collection and considering that tobacco-use behaviours could be expected to change along with pandemic-related changes in the social environment, the original design for the 2020 PATH Study data collection for youth and young adults was modified. Also, the PATH Study Adult Telephone Survey was developed to address the need for adult tobacco use monitoring in this unprecedented time. This article describes the modifications made to the 2020 PATH Study design and protocol to provide nationally representative data for youth and adults after the onset of the COVID-19 pandemic as well as the implications of these modifications for researchers.

Design and methods of the Population Assessment of Tobacco and Health (PATH) Study.

BACKGROUND: This paper describes the methods and conceptual framework for Wave 1 of the Population Assessment of Tobacco and Health (PATH) Study data collection. The National Institutes of Health, through the National Institute on Drug Abuse, is partnering with the Food and Drug Administration's (FDA) Center for Tobacco Products to conduct the PATH Study under a contract with Westat. METHODS: The PATH Study is a nationally representative, longitudinal cohort study of 45 971 adults and youth in the USA, aged 12 years and older. Wave 1 was conducted from 12 September 2013 to 15 December 2014 using Audio Computer-Assisted Self-Interviewing to collect information on tobacco-use patterns, risk perceptions and attitudes towards current and newly emerging tobacco products, tobacco initiation, cessation, relapse behaviours and health outcomes. The PATH Study's design allows for the longitudinal assessment of patterns of use of a spectrum of tobacco products, including initiation, cessation, relapse and transitions between products, as well as factors associated with use patterns. Additionally, the PATH Study collects biospecimens from consenting adults aged 18 years and older and measures biomarkers of exposure and potential harm related to tobacco use. CONCLUSIONS: The cumulative, population-based data generated over time by the PATH Study will contribute to the evidence base to inform FDA's regulatory mission under the Family Smoking Prevention and Tobacco Control Act and efforts to reduce the Nation's burden of tobacco-related death and disease.

Mutations in radial spoke head protein genes RSPH9 and RSPH4A cause primary ciliary dyskinesia with central-microtubular-pair abnormalities.

Primary ciliary dyskinesia (PCD) is a genetically heterogeneous inherited disorder arising from dysmotility of motile cilia and sperm. This is associated with a variety of ultrastructural defects of the cilia and sperm axoneme that affect movement, leading to clinical consequences on respiratory-tract mucociliary clearance and lung function, fertility, and left-right body-axis determination. We performed whole-genome SNP-based linkage analysis in seven consanguineous families with PCD and central-microtubular-pair abnormalities. This identified two loci, in two families with intermittent absence of the central-pair structure (chromosome 6p21.1, Zmax 6.7) and in five families with complete absence of the central pair (chromosome 6q22.1, Zmax 7.0). Mutations were subsequently identified in two positional candidate genes, RSPH9 on chromosome 6p21.1 and RSPH4A on chromosome 6q22.1. Haplotype analysis identified a common ancestral founder effect RSPH4A mutation present in UK-Pakistani pedigrees. Both RSPH9 and RSPH4A encode protein components of the axonemal radial spoke head. In situ hybridization of murine Rsph9 shows gene expression restricted to regions containing motile cilia. Investigation of the effect of knockdown or mutations of RSPH9 orthologs in zebrafish and Chlamydomonas indicate that radial spoke head proteins are important in maintaining normal movement in motile, "9+2"-structure cilia and flagella. This effect is rescued by reintroduction of gene expression for restoration of a normal beat pattern in zebrafish. Disturbance in function of these genes was not associated with defects in left-right axis determination in humans or zebrafish.

Charcot-Marie-Tooth disease: frequency of genetic subtypes and guidelines for genetic testing.

BACKGROUND: Charcot-Marie-Tooth disease (CMT) is a clinically and genetically heterogeneous group of diseases with approximately 45 different causative genes described. The aims of this study were to determine the frequency of different genes in a large cohort of patients with CMT and devise guidelines for genetic testing in practice. METHODS: The genes known to cause CMT were sequenced in 1607 patients with CMT (425 patients attending an inherited neuropathy clinic and 1182 patients whose DNA was sent to the authors for genetic testing) to determine the proportion of different subtypes in a UK population. RESULTS: A molecular diagnosis was achieved in 62.6% of patients with CMT attending the inherited neuropathy clinic; in 80.4% of patients with CMT1 (demyelinating CMT) and in 25.2% of those with CMT2 (axonal CMT). Mutations or rearrangements in PMP22, GJB1, MPZ and MFN2 accounted for over 90% of the molecular diagnoses while mutations in all other genes tested were rare. CONCLUSION: Four commonly available genes account for over 90% of all CMT molecular diagnoses; a diagnostic algorithm is proposed based on these results for use in clinical practice. Any patient with CMT without a mutation in these four genes or with an unusual phenotype should be considered for referral for an expert opinion to maximise the chance of reaching a molecular diagnosis.

Qualitative insights on how adult e-cigarette users describe quantity of e-cigarettes used - PATH Study 2018.

The purpose of this qualitative study was to gain a deeper understanding of how adult e-cigarette users describe quantity of e-cigarettes used. Data for this analysis came from a qualitative study of U.S. adult dual e-cigarette and cigarette users and former cigarette smokers aged 18 years and older. Eligible respondents from Wave 4 (2016-2017) of the Population Assessment of Tobacco and Health (PATH) Study responded to a brief web questionnaire and participated in an in-depth telephone interview (n = 112) between March and August 2018. Using the respondent's native terminology for their e-cigarette device, interviewers asked respondents to describe in their own words the quantity of e-cigarettes used. Using NVivo software, interview transcripts were coded and analyzed to identify themes and patterns. Respondents described quantity used in three different ways: number of times and/or puffs; device-specific terms (i.e., replacement of disposable devices, cartridges/pods; use of e-liquid); and perceived equivalence to a quantity of traditional cigarettes. The most commonly reported approach across all device types and levels of device proficiency, although with varying ease and specificity, was the number of times and/or puffs taken in a day. Several respondents used multiple approaches to describe quantity. E-cigarette users use a variety of approaches to describe quantity of e-cigarette used, contributing to challenges developing standardized survey measures. The variety of approaches should be taken into consideration along with device type and other contextual factors such as device proficiency when developing survey questions.

Founder mutation(s) in the RSPH9 gene leading to primary ciliary dyskinesia in two inbred Bedouin families.

A rare mutation in the RSPH9 gene leading to primary ciliary dyskinesia was previously identified in two Bedouin families, one from Israel and one from the United Arab Emirates (UAE). Herein we analyse mutation segregation in the Israeli family, present the clinical disease spectrum, and estimate mutation age in the two families. Mutation segregation was studied by restriction fragment length analysis. Mutation ages were estimated using a model of the decrease in the length of ancestral haplotypes. The mutations in each of the two families had a common ancestor less than 95 and less than 17 generations in the past. If the mutations in the two families are descended from a common ancestor, that mutation would have to have arisen at least 150 generations ago. If the Bedouin population has been roughly constant in size for at least 6000 years, it is possible that the mutations in the two families are identical by descent. If there were substantial fluctuations in the size of the Bedouin population, it is more likely that there were two independent mutations. Based on the available data, the population genetic analysis does not strongly favour one conclusion over the other.

CCDC103 mutations cause primary ciliary dyskinesia by disrupting assembly of ciliary dynein arms.

Cilia are essential for fertilization, respiratory clearance, cerebrospinal fluid circulation and establishing laterality. Cilia motility defects cause primary ciliary dyskinesia (PCD, MIM244400), a disorder affecting 1:15,000-30,000 births. Cilia motility requires the assembly of multisubunit dynein arms that drive ciliary bending. Despite progress in understanding the genetic basis of PCD, mutations remain to be identified for several PCD-linked loci. Here we show that the zebrafish cilia paralysis mutant schmalhans (smh(tn222)) encodes the coiled-coil domain containing 103 protein (Ccdc103), a foxj1a-regulated gene product. Screening 146 unrelated PCD families identified individuals in six families with reduced outer dynein arms who carried mutations in CCDC103. Dynein arm assembly in smh mutant zebrafish was rescued by wild-type but not mutant human CCDC103. Chlamydomonas Ccdc103/Pr46b functions as a tightly bound, axoneme-associated protein. These results identify Ccdc103 as a dynein arm attachment factor that causes primary ciliary dyskinesia when mutated.