Vitiligo pathogenesis: autoimmune disease, genetic defect, excessive reactive oxygen species, calcium imbalance, or what else?

The pathobiology of vitiligo has been hotly disputed for as long as one remembers, and has been a magnet for endless speculation. Evidently, the different schools of thought--ranging, e.g. from the concept that vitiligo essentially is a free-radical disorder to that of vitiligo being a primary autoimmune disease--imply very different consequences for the best therapeutic strategies that one should adopt. As a more effective therapy for this common, often disfiguring pigmentary disorder is direly needed, we must strive harder to settle the pathogenesis debate definitively--on the basis of sound experimental evidence, rather than by a war of dogmatic theories. Recognizing, however, that it is theories which tend to guide our experimental designs and choice of study parameters, the various pathogenesis theories on the market deserve to be critically, yet unemotionally re-evaluated. This Controversies feature invites you to do so, and to ask yourself: is there something important or worthwhile exploring in other pathogenesis scenarios than those already favoured by you that may help you improve your own study design, next time you have a fresh look at vitiligo? Vitiligo provides a superb model for the study of many fundamental problems in skin biology and pathology. Therefore, even if it later turns out that, as far as your own vitiligo pathogenesis concept is concerned, you have barked-up the wrong tree most of the time, chances are that you shall anyway have generated priceless new insights into skin function along the way.

Association between mannose binding lectin polymorphisms and predisposition to bacterial meningitis

The aim of this study was to examine the presence of any association between mannose binding lectin (MBL) gene variants and bacterial meningitis. Codon 54 (B allele) and codon 57 (C allele) polymorphisms in exon 1 of the MBL gene were investigated in 50 healthy controls and 31 patients diagnosed as purulent meningitis. Codon 57 polymorphism was not found in our patient and control groups. B allele frequency was significantly higher in the patient group (22%) compared to the control group (3%). AB genotype was determined in 39% and 6% of patient and healthy control groups, respectively, and the difference was statistically significant. AA genotype was determined in 61% of the patient group and in 94% of the control group, and it was statistically low in the patient group. These results suggest that codon 54 polymorphism in the MBL gene may play a role in susceptibility to bacterial meningitis in children.

Duane anomaly, meningomyelocele, dextroposition of heart and localized vertebrocostal alterations with associated anomalies in a girl

Vertebral and rib anomalies occur because of defects at different stages of embryo development and result in different malformations. Developmental field defects are the term to describe the alterations in the biological units which occur because of defects in the pattern formation. Short trunk dwarfism associated with vertebral and rib anomalies is one of the well-known conditions described under various names. Here we report on a 20-month-old female with short trunk dwarfism involving an asymmetrically malformed thorax with kyphoscoliosis presenting skeletal anomalies of spine and ribs and additional multiple associated anomalies such as downslanting palpebral fissures, long philtrum, high palate, rocker bottom feet, dextroposition of heart, cascade stomach, retroposition of bulbi duodeni and bilateral renal cortical thinning. Ophthalmological examination revealed Duane anomaly. No mutation was detected in the analysis of the DLL3 gene. The malformations in the patient are related to different progenitor fields in the early development of the embryo and the presented combination of Duane anomaly with the associated anomalies has not been reported in the literature.

Prenatal diagnosis of de novo unbalanced translocation 8p;21q using subtelomeric probes

We report an unbalanced translocation involving chromosomes 8 and 21 in a fetus showing ultrasonographic abnormalities in the second trimester of pregnancy. A 41-year-old pregnant woman, gravida 1 para 0, was referred to the Genetics Clinic at the 16th week of gestation because of advanced maternal age and fetal pelvicaliectasis on ultrasonographic examination. Pregnancy had occurred following ICSI treatment. After genetic counseling amniocentesis was performed. Fetal karyotype analysis revealed a 46,XY,8p+ karyotype. Ultrasonographic examination was repeated at the 20th week of gestation and showed intrauterine growth retardation, ventriculomegaly, cerebellar structural abnormality and pelvicaliectasis. Chromosomes of both parents were normal. Molecular cytogenetic studies (FISH) using chromosome-specific subtelomere probes showed a terminal deletion of 8p and trisomy of the 21q subtelomeric region. Further analysis with Down Syndrome specific region probes revealed two signals. The couple decided to terminate the pregnancy. This is the first prenatally diagnosed case of unbalanced t(8p;21q) of de novo origin.

Chromosomal rearrangements in children with idiopathic mental retardation using subtelomeric fluorescent in situ hybridization

To screen a selected group of children with idiopathic mental retardation for subtelomeric abnormalities using the fluorescent in situ hybridization (FISH), which has been reported to be cost-effective in routine applications. We also aimed to assess the availability of the scoring system which is used for selection of those children for FISH analysis. A total of 30 children aged 3-16 years with idiopathic mental retardation (moderate to severe) and normal karyotypes were included in this study. The children whose parents had consanguineous marriages were excluded from the study. All cases were evaluated using the scoring system published by de Vries et al. (5) Forty-one subtelomeric regions for each case were analyzed by fluorescent in situ hybridization. One case with a score value 5 presented terminal deletion of chromosome 9p by FISH (3.3 %). Analyzing chromosomes of the same case with higher resolution G-banding showed the same abnormality. The frequency of subtelomeric abnormalities in our study group was much lower than the frequencies reported in other studies and the scoring criterions suggested by de Vries et al. have not effectively increased our subtelomeric deletion detection rates. Autosomal recessive disorders may be a more common reason compared to subtelomeric abnormalities in this group of patients in the countries where consanguinity rate is high. Laboratories may be encouraged to analyze high-resolution G-banded karyotypes in those cases. Moreover more effective selection criteria for FISH are suggested by establishing thorough genotype-phenotype correlations besides case reports with different subtelomeric abnormalities.

Two extra euchromatic bands in the qh region of chromosome 9

Chromosome analysis in a fetus revealed an abnormal appearance of chromosome 9. The secondary constriction region of chromosome 9 was very large and two separate G+ bands were observed within this region with GTG banding. Parents' karyotypes showed maternal inheritance of this variant chromosome 9. Two G+ bands were stained negative with C banding both in the fetus and in the mother. The mother was phenotypically normal. Regarding phenotypically normal mother, normal fetal ultrasonographic findings and the similar cases described before in the literature it was considered that the fetus would be normal. Physical examination of the baby was normal after birth as expected. The existence of two G+ bands in 9qh was considered to be a normal variant in humans.

Trends in cytogenetic prenatal diagnosis in a reference hospital in Izmir/Turkey: a comparative study for four years

The aim of the study was to investigate the major changes in the indications, culture success and abnormality rate for conventional cytogenetic prenatal diagnosis on amniotic fluid samples between the period of January 1998 and December 2001 in Izmir. The cytogenetic laboratory provides a prenatal service to obstetrics-gynecology departments of different hospitals in Izmir. A limited number of patients (6-8 per week) is randomly accepted for prenatal cytogenetic study. Over the 4 years period 1190 prenatal cytogenetic tests were performed in our center. The most common indication was advanced maternal age for each year. However its rate has increased significantly within the years (35.68% in 1998, 61.38% in 2001), while the rate of both triple test and ultrasound scanning indications decreased. Culture success rates have improved (97.97% in 1998, 99.74% in 2001). Comparing the first two years to the last two years the rate of abnormal cytogenetic results decreased significantly (3.83% in 1998-99, 2.48% in 2000-01). The major reason for this decrease is probably related to the changes in indications throughout the years.

Why is lip augmentation with autologous fat injection less effective in the vermilion border?

Lip augmentation is a well tolerated procedure leading to a more youthful appearance. Augmentation of lips is most frequently performed with autologous tissue, biomaterials, or alloplastic materials. Autologous fat grafting is a simple procedure because of the ease of harvesting and subsequent injection into selected sites. Fat injection is suitable for the bulk of the red lips, but is less effective for the vermilion border. This study was performed to determine why fat injection is less effective for the vermilion border.