Biallelic KITLG variants lead to a distinct spectrum of hypomelanosis and sensorineural hearing loss

BACKGROUND: Pathogenic variants in KITLG, a crucial protein involved in pigmentation and neural crest cell migration, cause non-syndromic hearing loss, Waardenburg syndrome type 2, familial progressive hyperpigmentation and familial progressive hyper- and hypopigmentation, all of which are inherited in an autosomal dominant manner. OBJECTIVES: To describe the genotypic and clinical spectrum of biallelic KITLG-variants. METHODS: We used a genotype-first approach through the GeneMatcher data sharing platform to collect individuals with biallelic KITLG variants and reviewed the literature for overlapping reports. RESULTS: We describe the first case series with biallelic KITLG variants; we expand the known hypomelanosis spectrum to include a 'sock-and-glove-like', symmetric distribution, progressive repigmentation and generalized hypomelanosis. We speculate that KITLG biallelic loss-of-function variants cause generalized hypomelanosis, whilst variants with residual function lead to a variable auditory-pigmentary disorder mostly reminiscent of Waardenburg syndrome type 2 or piebaldism. CONCLUSIONS: We provide consolidating evidence that biallelic KITLG variants cause a distinct auditory-pigmentary disorder. We evidence a significant clinical variability, similar to the one previously observed in KIT-related piebaldism

Identifying Consensus Disease Pathways in Parkinson's Disease Using an Integrative Systems Biology Approach

Parkinson's disease (PD) has had six genome-wide association studies (GWAS) conducted as well as several gene expression studies. However, only variants in MAPT and SNCA have been consistently replicated. To improve the utility of these approaches, we applied pathway analyses integrating both GWAS and gene expression. The top 5000 SNPs (p<0.01) from a joint analysis of three existing PD GWAS were identified and each assigned to a gene. For gene expression, rather than the traditional comparison of one anatomical region between sets of patients and controls, we identified differentially expressed genes between adjacent Braak regions in each individual and adjusted using average control expression profiles. Over-represented pathways were calculated using a hyper-geometric statistical comparison. An integrated, systems meta-analysis of the over-represented pathways combined the expression and GWAS results using a Fisher's combined probability test. Four of the top seven pathways from each approach were identical. The top three pathways in the meta-analysis, with their corrected p-values, were axonal guidance (p = 2.8E-07), focal adhesion (p = 7.7E-06) and calcium signaling (p = 2.9E-05). These results support that a systems biology (pathway) approach will provide additional insight into the genetic etiology of PD and that these pathways have both biological and statistical support to be important in PD

A syndromic neurodevelopmental disorder caused by rare variants in PPFIA3

PPFIA3 encodes the protein-tyrosine phosphatase, receptor-type, F-polypeptide-interacting-protein-alpha-3 (PPFIA3), which is a member of the LAR-protein-tyrosine phosphatase-interacting-protein (liprin) family involved in synapse formation and function, synaptic vesicle transport, and presynaptic active zone assembly. The protein structure and function are evolutionarily well conserved, but human diseases related to PPFIA3 dysfunction are not yet reported in OMIM. Here, we report 20 individuals with rare PPFIA3 variants (19 heterozygous and 1 compound heterozygous) presenting with developmental delay, intellectual disability, hypotonia, dysmorphisms, microcephaly or macrocephaly, autistic features, and epilepsy with reduced penetrance. Seventeen unique PPFIA3 variants were detected in 18 families. To determine the pathogenicity of PPFIA3 variants in vivo, we generated transgenic fruit flies producing either human wild-type (WT) PPFIA3 or five missense variants using GAL4-UAS targeted gene expression systems. In the fly overexpression assays, we found that the PPFIA3 variants in the region encoding the N-terminal coiled-coil domain exhibited stronger phenotypes compared to those affecting the C-terminal region. In the loss-of-function fly assay, we show that the homozygous loss of fly Liprin-α leads to embryonic lethality. This lethality is partially rescued by the expression of human PPFIA3 WT, suggesting human PPFIA3 function is partially conserved in the fly. However, two of the tested variants failed to rescue the lethality at the larval stage and one variant failed to rescue lethality at the adult stage. Altogether, the human and fruit fly data reveal that the rare PPFIA3 variants are dominant-negative loss-of-function alleles that perturb multiple developmental processes and synapse formation

Comprehensive analysis via exome sequencing uncovers genetic etiology in autosomal recessive nonsyndromic deafness in a large multiethnic cohort

Purpose:Autosomal recessive nonsyndromic deafness (ARNSD) is characterized by a high degree of genetic heterogeneity, with reported mutations in 58 different genes. This study was designed to detect deafness-causing variants in a multiethnic cohort with ARNSD by using whole-exome sequencing (WES).Methods:After excluding mutations in the most common gene, GJB2, we performed WES in 160 multiplex families with ARNSD from Turkey, Iran, Mexico, Ecuador, and Puerto Rico to screen for mutations in all known ARNSD genes.Results:We detected ARNSD-causing variants in 90 (56) families, 54 of which had not been previously reported. Identified mutations were located in 31 known ARNSD genes. The most common genes with mutations were MYO15A (13), MYO7A (11), SLC26A4 (10), TMPRSS3 (9), TMC1 (8), ILDR1 (6), and CDH23 (4). Nine mutations were detected in multiple families with shared haplotypes, suggesting founder effects.Conclusion:We report on a large multiethnic cohort with ARNSD in which comprehensive analysis of all known ARNSD genes identifies causative DNA variants in 56 of the families. In the remaining families, WES allows us to search for causative variants in novel genes, thus improving our ability to explain the underlying etiology in more families.Genet Med 18 4, 364-371. © American College of Medical Genetics and Genomics

First illustrations of female "Neurosurgeons" in the fifteenth century by Serefeddin

Los hombres han dominado la medicina durante muchos siglos. Las mujeres no aparecen en la historia de la medicina hasta el final del siglo XVIII, aunque siempre han estado en la medicina como curanderas. Vale la pena mencionar que las primeras ilustraciones que indican la presencia de mujeres en la cirugía se encontraron en un libro escrito en turco por Serefeddin Sabuncuoglu en el siglo XV, mientras Europa todavía despertaba de la oscuridad y el Oriente Medio estaba bajo la influencia de las estrictas reglas de la cultura Arábiga e Islámica. Serefeddin Sabuncuoglu (1385- 1470) fue el autor del primer texto quirúrgico ilustrado Cerrahiyyetu'l-Haniyye (Cirugía Imperial) en Literatura Turca. Las miniaturas dibujadas por Sereffeddin Sabuncuoglu indicaban que las mujeres cirujanos, conocidas como "Tabibe", estaban autorizadas para practicar sólo en Anatolia. Se ilustra, en miniaturas, cómo las Tabibes actuaban en el tratamiento de fetos muertos con hidrocefalia y macrocefalia que fueron, por supuesto, los primeros datos de mujeres turcas en la Neurocirugía

First illustrations of female "Neurosurgeons" in the fifteenth century by Serefeddin Sabuncuoglu

WOS: 000238561100015PubMed: 16721484Males have dominated medicine for many centuries. Females could not appear in the medical history equally till the end of the 18(th) century; although they always have been in medicine as healers. It is worth mentioning that first illustrations indicating female surgeons were found in the book written in Turkish by Serefeddin Sabuncuoglu in the 15(th) century; while Europe was newly waking up from its dark ages and Middle East was under the influence of strict rules of Arabic and Islamic culture. Serefeddin Sabuncuoglu (1385-1470) was the author of the first illustrated surgical textbook Cerrahiyyetu'l-Haniyye (Imperial surgery) in Turkish Literature

Postoperative spinal ultrasonography findings in spinal dysraphia

PubMed: 16206054Diastematomyelia is a form of spinal dysraphism involving sagittal clefting of the spinal cord, conus medullaris, and/or filum terminale into two hemicords. It can be an isolated finding or can be associated with meningomyelocele or meningocele. In this report, we present postoperative spinal ultrasonography findings in a patient with diastematomyelia and a tethered cord. © Turkish Society of Radiology 2005

Faun Tail: Diagnosis of Occult Spinal Dysraphism with a Rare Cutaneous Marker [4]

PubMed: 15187350[No abstract available