Gender and wavefront higher order aberrations: do the genders see the world differently?

INTRODUCTION: wavefront sensing technology has emerged as a means to advance our understanding of high-order aberrations of the human eye. PURPOSE: to evaluate the differences in ocular high-order aberrations between males and females and the distribution of high-order aberrations in males and females. SUBJECTS AND METHODS: 3,597 eyes (1,029 female and 2,568 male) of 1,874 patients who obtained wavefront measurements performed using the VISX Wavescan device were included in this study. Mean RMS (root mean square) values of high-order aberrations (HOAs) and the mean of each Zernike polynomial from the second to the sixth order were calculated from multiple scans of each eye. Analysis was performed to assess the association between HOAs and gender, and symmetry of HOAs between eyes in both males and females. RESULTS: overall HOA did not differ significantly between males and females (p= 0.93). Overall HOA did not differ between left eyes (p=0.852) or right eyes (p=0.76). Individual Zernike polynomials did reveal a significant difference between male and female eyes: Z14 (Tetrafoil x, p=.036); Z16 (Secondary Trefoil y, p=0.015); Z24 (Secondary Spherical, p-=0.003); Z25 (Tertiary Astigmatism x, p=0.010); and Z26 (Secondary Tetrafoil x, p=0.004). CONCLUSION: overall HOA does not differ between the genders; however, individual HOA Zernike terms do demonstrate statistically significant differences between males and females. This is the first such study to describe these differences. The clinical significance of these differences has yet to be determined.

Genetic variants in the IMPA2 gene do not confer increased risk of febrile seizures in Caucasian patients.

Pathogenesis of febrile seizures (FS), causing the most common of types of seizures in children, remains unknown. Genetic factors appear to play a pivotal role and FS can be inherited as a monogenic or genetically complex disorder. Several risks factors have been proposed but many of the previously reported genetic associations were not replicated. Non-coding polymorphisms in the myo-inositol monophosphatase 2 gene (IMPA2) have been suggested as a susceptibility factor for FS in Japanese patients. It is unknown whether genetic variants in the same gene constitute a risk factor for FS in other ethnic groups because the frequency of FS is significantly higher in Japanese children than in Caucasian patients. We investigated the role of the IMPA2 gene in a cohort of 96 unrelated Caucasian subjects with a history of FS. We did not identify any significant differences in genotypes of cases and matched controls; no mutations or non-synonymous polymorphisms were detected in these individuals. Our data suggest that the genetic variants in the IMPA2 gene are not associated with a risk of FS in Caucasian patients and patients from various genetic groups are likely to have different genetic causes of FS.

Familial mesial temporal lobe epilepsy maps to chromosome 4q13.2-q21.3.

PURPOSE: To report results of linkage analysis in a large family with autosomal dominant (AD) familial mesial temporal lobe epilepsy (FMTLE). BACKGROUND: Although FMTLE is a heterogeneous syndrome, one important subgroup is characterized by a relatively benign course, absence of antecedent febrile seizures, and absence of hippocampal sclerosis. These patients have predominantly simple partial seizures (SPS) and infrequent complex partial seizures (CPS), and intense and frequent déjà vu phenomenon may be the only manifestation of this epilepsy syndrome. No linkage has been described in this form of FMTLE. METHODS: We identified a four-generation kindred with several affected members meeting criteria for FMTLE and enrolled 21 individuals who gave informed consent. Every individual was personally interviewed and examined; EEG and MRI studies were performed on three affected subjects. DNA was extracted from every enrolled individual. We performed a genome-wide search using an 8 cM panel and fine mapping was performed in the regions with a multipoint lod score >1. We sequenced the highest priority candidate genes. RESULTS: Inheritance was consistent with AD mode with reduced penetrance. Eleven individuals were classified as affected with FMTLE and we also identified two living asymptomatic individuals who had affected offspring. Seizure semiologies included predominantly SPS with déjà vu feeling, infrequent CPS, and rare secondarily generalized tonic-clonic seizures. No structural abnormalities, including hippocampal sclerosis, were detected on MRI performed on three individuals. Genetic analysis detected a group of markers with lod score >3 on chromosome 4q13.2-q21.3 spanning a 7 cM region. No ion channel genes are predicted to be localized within this locus. We sequenced all coding exons of sodium bicarbonate cotransporter (SLC4A) gene, which plays an important role in tissue excitability, and cyclin I (CCNI), because of its role in the cell migration and possibility of subtle cortical abnormalities. No disease-causing mutations were identified in these genes. CONCLUSION: We report identification of a genetic locus for familial mesial temporal lobe epilepsy. The identification of a disease-causing gene will contribute to our understanding of the pathogenesis of temporal lobe epilepsies.