Light scattering measurement and Avrami analysis of the lamellar to inverse hexagonal phase transition kinetics of the lipid DEPE.

The lamellar to inverse hexagonal phase transition of lipids is much studied as a model for understanding cellular processes such as membrane fusion and pore formation. Much remains unknown, including a theoretical understanding and a definitive value of the phase transition temperature for DEPE, as literature values vary over 10°C. Avrami theory has been commonly used to analyze phase transition kinetics.

Connexin43 mutation causes heterogeneous gap junction loss and sudden infant death.

Background: An estimated 10% to 15% of sudden infant death syndrome (SIDS) cases may stem from channelopathy-mediated lethal arrhythmias. Loss of the GJA1-encoded gap junction channel protein connexin43 is known to underlie formation of lethal arrhythmias. GJA1 mutations have been associated with cardiac diseases, including atrial fibrillation.

LQTS-associated mutation A257G in α1-syntrophin interacts with the intragenic variant P74L to modify its biophysical phenotype.

The -encoded α1-syntrophin (SNTA1) missense mutation, p.A257G, causes long QT syndrome (LQTS) by pathogenic accentuation of Nav1.5's sodium current ().

Genomic risk factors in sudden infant death syndrome.

Sudden infant death syndrome (SIDS) is a major contributor to postneonatal infant death, and is the third leading cause of infant mortality in the USA. While public health efforts have reduced these deaths in recent years, the pathogenesis of SIDS remains unclear. Epidemiological data on SIDS-related deaths have suggested genetic factors, and many studies have attempted to identify SIDS-associated genes.

Sudden infant death syndrome-associated mutations in the sodium channel beta subunits.

Background: Approximately 10% of sudden infant death syndrome (SIDS) cases may stem from potentially lethal cardiac channelopathies, with approximately half of channelopathic SIDS involving the Na(V)1.5 cardiac sodium channel. Recently, Na(V) beta subunits have been implicated in various cardiac arrhythmias.

Alpha1-syntrophin mutations identified in sudden infant death syndrome cause an increase in late cardiac sodium current.

Background: Sudden infant death syndrome (SIDS) is a leading cause of death during the first 6 months after birth. About 5% to 10% of SIDS may stem from cardiac channelopathies such as long-QT syndrome. We recently implicated mutations in alpha1-syntrophin (SNTA1) as a novel cause of long-QT syndrome, whereby mutant SNTA1 released inhibition of associated neuronal nitric oxide synthase by the plasma membrane Ca-ATPase PMCA4b, causing increased peak and late sodium current (I(Na)) via S-nitrosylation of the cardiac sodium channel.

Overrepresentation of the proarrhythmic, sudden death predisposing sodium channel polymorphism S1103Y in a population-based cohort of African-American sudden infant death syndrome.

Background: The S1103Y-SCN5A polymorphism has been implicated as a proarrhythmic, sudden death predisposing risk factor in African Americans, including one postmortem investigation of African-American infants with sudden infant death syndrome (SIDS).

Objective: The purpose of this study was to assess whether the relatively African-American-specific common polymorphism S1103Y in the SCN5A-encoded cardiac sodium channel is overrepresented in SIDS among African Americans.

Methods: Seventy-one cases from a population-based cohort of unexplained infant deaths among African Americans (37 females and 34 males, average age 3 +/- 2 months, age range birth to 11 months) were submitted to the Mayo Clinic Windland Smith Rice Sudden Death Genomics Laboratory for postmortem genetic testing.

Molecular and functional characterization of novel glycerol-3-phosphate dehydrogenase 1 like gene (GPD1-L) mutations in sudden infant death syndrome.

Background: Autopsy-negative sudden unexplained death, including sudden infant death syndrome, can be caused by cardiac channelopathies such as Brugada syndrome (BrS). Type 1 BrS, caused by mutations in the SCN5A-encoded sodium channel, accounts for approximately 20% of BrS. Recently, a novel mutation in the glycerol-3-phosphate dehydrogenase 1-like gene (GPD1-L) disrupted trafficking of SCN5A in a multigenerational family with BrS.