Evidence that the Ser192Tyr/Arg402Gln in cis Tyrosinase gene haplotype is a disease-causing allele in oculocutaneous albinism type 1B (OCA1B).

Oculocutaneous albinism type 1 (OCA1) is caused by pathogenic variants in the TYR (tyrosinase) gene which encodes the critical and rate-limiting enzyme in melanin synthesis. It is the most common OCA subtype found in Caucasians, accounting for ~50% of cases worldwide. The apparent 'missing heritability' in OCA is well described, with ~25-30% of clinically diagnosed individuals lacking two clearly pathogenic variants. Here we undertook empowered genetic studies in an extensive multigenerational Amish family, alongside a review of previously published literature, a retrospective analysis of in-house datasets, and tyrosinase activity studies. Together this provides irrefutable evidence of the pathogenicity of two common TYR variants, p.(Ser192Tyr) and p.(Arg402Gln) when inherited in cis alongside a pathogenic TYR variant in trans. We also show that homozygosity for the p.(Ser192Tyr)/p.(Arg402Gln) TYR haplotype results in a very mild, but fully penetrant, albinism phenotype. Together these data underscore the importance of including the TYR p.(Ser192Tyr)/p.(Arg402Gln) in cis haplotype as a pathogenic allele causative of OCA, which would likely increase molecular diagnoses in this missing heritability albinism cohort by 25-50%.

No association between SCN9A and monogenic human epilepsy disorders.

Many studies have demonstrated the clinical utility and importance of epilepsy gene panel testing to confirm the specific aetiology of disease, enable appropriate therapeutic interventions, and inform accurate family counselling. Previously, SCN9A gene variants, in particular a c.1921A>T p.(Asn641Tyr) substitution, have been identified as a likely autosomal dominant cause of febrile seizures/febrile seizures plus and other monogenic seizure phenotypes indistinguishable from those associated with SCN1A, leading to inclusion of SCN9A on epilepsy gene testing panels. Here we present serendipitous findings of genetic studies that identify the SCN9A c.1921A>T p.(Asn641Tyr) variant at high frequency in the Amish community in the absence of such seizure phenotypes. Together with findings in UK Biobank these data refute an association of SCN9A with epilepsy, which has important clinical diagnostic implications.

Phenotypic Variability in Atherosclerosis Burden in an Old-Order Amish Family With Homozygous Sitosterolemia.

Sitosterolemia is a rare atherogenic sterol storage disease with variability in its presentation requiring a high degree of clinical suspicion. We present 8 cases of sitosterolemia from an Amish kindred that, despite a background of decreased genetic and lifestyle variability, still had markedly variable presentations. (Level of Difficulty: Advanced.).

Newborn Screening for Inherited Metabolic Disorders: Early Identification and Long-Term Care for Patients in the Plain Community, Wisconsin, 2011-2017.

The Plain community is the fastest-growing religious minority in Wisconsin. This community has a high incidence of genetic disorders, many of which are identifiable through newborn screening. We describe efforts by the Wisconsin Newborn Screening Program (WNSP) to improve health care in the Plain community by targeting early identification of, and intervention for, patients with inherited metabolic disorders. WNSP formed partnerships with families and health care providers to increase awareness of screening procedures and the intended benefits of screening, modify testing algorithms to enhance detection, and establish medical homes for patients with confirmed disorders. The estimated number of Plain newborns screened increased by 25.5% during the study period, from 547 in 2011 to 736 in 2017; 122 persons underwent carrier testing, and 143 newborns received second-tier testing. From 2014 to 2017, affected patients received 71 metabolic evaluations in their community medical home without travel to major health centers. This article demonstrates how a comprehensive public health program can help increase screening rates, enhance detection, and establish follow-up care in a hard-to-reach religious community. A key lesson learned was the importance of communication among all stakeholders to develop an effective public health program.

Recessive GM3 synthase deficiency: Natural history, biochemistry, and therapeutic frontier.

GM3 synthase, encoded by ST3GAL5, initiates synthesis of all downstream cerebral gangliosides. Here, we present biochemical, functional, and natural history data from 50 individuals homozygous for a pathogenic ST3GAL5 c.862C>T founder allele (median age 8.1, range 0.7-30.5 years). GM3 and its derivatives were undetectable in plasma. Weight and head circumference were normal at birth and mean Apgar scores were 7.7 ±â€¯2.0 (1 min) and 8.9 ±â€¯0.5 (5 min). Somatic growth failure, progressive microcephaly, global developmental delay, visual inattentiveness, and dyskinetic movements developed within a few months of life. Infantile-onset epileptic encephalopathy was characterized by a slow, disorganized, high-voltage background, poor state transitions, absent posterior rhythm, and spike trains from multiple independent cortical foci; >90% of electrographic seizures were clinically silent. Hearing loss affected cochlea and central auditory pathways and 76% of children tested failed the newborn hearing screen. Development stagnated early in life; only 13 (26%) patients sat independently (median age 30 months), three (6%) learned to crawl, and none achieved reciprocal communication. Incessant irritability, often accompanied by insomnia, began during infancy and contributed to high parental stress. Despite catastrophic neurological dysfunction, neuroimaging showed only subtle or no destructive changes into late childhood and hospitalizations were surprisingly rare (0.2 per patient per year). Median survival was 23.5 years. Our observations corroborate findings from transgenic mice which indicate that gangliosides might have a limited role in embryonic neurodevelopment but become vital for postnatal brain growth and function. These results have critical implications for the design and implementation of ganglioside restitution therapies.

Cross-Sectional Survey on Newborn Screening in Wisconsin Amish and Mennonite Communities.

Old Order Amish and Mennonites, or Plain populations, are a growing minority in North America with unique health care delivery and access challenges coupled with higher frequencies of genetic disorders. The objective of this study was to determine newborn screening use and attitudes from western Wisconsin Plain communities. A cross-sectional survey, with an overall response rate of 25 %, provided data representing 2010 children. In households with children (n = 297), the rate of newborn screening was 74 % and all children were screened in 40 % of these households. Lack of access to testing was the most common reason for not screening all children and parental age was inversely associated with testing. The majority of respondents reported some or more knowledge of screening, viewed screening as important, and had access to screening in their communities. Households with children who had never received newborn screening (26 %) reported lower frequencies of favorable responses in all categories compared to households that had at least one child screened. The difference in access to newborn screening was less marked between the groups compared to differences on knowledge and consideration of its importance. Moreover, 55 % of households who had never screened any of their children reported being unlikely or unsure of screening any future children. A focus on improving access to newborn screening alongside establishing approaches to change parental perceptions on the importance of newborn screening is necessary for increasing newborn screening in these Plain communities.

Successful pregnancy and delivery in a woman with propionic acidemia from the Amish community.

Propionic acidemia (PA) is an inborn error of protein metabolism with a variable clinical presentation ranging from neonatal encephalopathy to seemingly asymptomatic individuals who present with cardiomyopathy or sudden death. PA is recognized in the Amish population, often with an early asymptomatic course and eventual cardiac complications. Thus, Amish women with PA may reach reproductive age without clinical sequelae, but are at increased risk for metabolic decompensation during pregnancy, delivery and postpartum period. We describe the care of an Amish woman with PA during her first pregnancy and delivery.

Characterization of TATP gas phase product ion chemistry via isotope labeling experiments using ion mobility spectrometry interfaced with a triple quadrupole mass spectrometer.

Identification of the fragment ion species associated with the ion reaction mechanism of triacetone triperoxide (TATP), a homemade peroxide-based explosive, is presented. Ion mobility spectrometry (IMS) has proven to be a key analytical technique in the detection of trace explosive material. Unfortunately, IMS alone does not provide chemical identification of the ions detected; therefore, it is unknown what ion species are actually formed and separated by the IMS. In IMS, ions are primarily characterized by their drift time, which is dependent on the ion׳s mass and molecular cross-section; thus, IMS as a standalone technique does not provide structural signatures, which is in sharp contrast to the chemical and molecular information that is generally obtained from other customary analytical techniques, such as NMR, Raman and IR spectroscopy and mass spectrometry. To help study the ion chemistry that gives rise to the peaks observed in IMS, the hardware of two different commercial IMS instruments has been directly coupled to triple quadrupole (QQQ) mass spectrometers, in order to ascertain each ion׳s corresponding mass/charge (m/z) ratios with different dopants at two temperatures. Isotope labeling was then used to help identify and confirm the molecular identity of the explosive fragment and adduct ions of TATP. The m/z values and isotope labeling experiments were used to help propose probable molecular formulas for the ion fragments. In this report, the fragment and adduct ions m/z 58 and 240 of TATP have been confirmed to be [C3H6NH·H](+) and [TATP·NH4](+), respectively; while the fragment ions m/z 73 and 89 of TATP are identified as having the molecular formulas [C4H9NH2](+) and [C4H9O2](+), respectively. It is anticipated that the work in this area will not only help to facilitate improvements in mobility-based detection (IMS and MS), but also aid in the development and optimization of MS-based detection algorithms for TATP.

Low primary cesarean rate and high VBAC rate with good outcomes in an Amish birthing center.

PURPOSE: Recent national guidelines encourage a trial of labor after cesarean (TOLAC) as a means of increasing vaginal births after cesarean (VBACs) and decreasing the high US cesarean birth rate and its consequences (2010 National Institute of Health Consensus Statement and American College of Obstetricians and Gynecologists revised guideline). A birthing center serving Amish women in Southwestern Wisconsin offered an opportunity to look at the effects of local culture and practices that support vaginal birth and TOLAC. This study describes childbirth and perinatal outcomes during a 17-year period in LaFarge, Wisconsin. METHODS: We undertook a retrospective analysis of the records of all women admitted to the birth center in labor. Main outcome measures include rates of cesarean deliveries, TOLAC and VBAC deliveries, and perinatal outcomes for 927 deliveries between 1993 and 2010. RESULTS: The cesarean rate was 4% (35 of 927), the TOLAC rate was 100%, and the VBAC rate was 95% (88 of 92). There were no cases of uterine rupture and no maternal deaths. The neonatal death rate of 5.4 of 1,000 was comparable to that of Wisconsin (4.6 of 1,000) and the United States (4.5 of 1,000). CONCLUSIONS: Both the culture of the population served and a number of factors relating to the management of labor at the birthing center have affected the rates of cesarean delivery and TOLAC. The results of the LaFarge Amish study support a low-technology approach to delivery where good outcomes are achieved with low cesarean and high VBAC rates.

Clustering of recurrent pericarditis with effusion and constriction in a family.

OBJECTIVE: To describe a cluster of cases of pericarditis in a midwestern family of German and Danish ancestry. PATIENTS AND METHODS: Retrospective review of available medical records identified 5 family members in 2 generations with confirmed diagnosis of pericarditis. RESULTS: Five family members, 3 males and 2 females, presented for medical evaluation of recurrent chest pain between 1969 and 1991. Physical examination resulted in the diagnosis of pericarditis with effusive and constrictive features. The age at presentation ranged from 8 to 46 years. Despite extensive investigations, an idiopathic etiology was assigned to each case. In follow-up, all 5 family members had recurrent episodes of chest pain, self-limiting or responsive to medical therapy, but the effusive component remained a notable feature of the syndrome. CONCLUSIONS: Diagnosis of pericarditis in 5 family members may represent the first description of familial clustering of isolated pericarditis. In addition, 3 other family members had symptoms of chest pain, but pericarditis remained undiagnosed. The aggregate history suggests autosomal dominant inheritance with incomplete penetrance.