High Degree Of Phenotypic Variability Research Articles

A novel heterozygous mutation in PTHLH causing autosomal dominant brachydactyly type E complicated with short stature.

Brachydactyly type E (BDE) is a general term characterized by variable shortening of metacarpals and metatarsals, with phalanges affected frequently. It can occur as an isolated form or part of syndromes and manifest a high degree of phenotypic variability. In this study, we have identified the clinical characteristics and pathogenic causes of a four-generation pedigree with 10 members affected by BDE and short stature. After the informed consent was signed, clinical data and peripheral blood samples were collected from available family members. Karyotype analysis, array-CGH, next-generation sequencing, and Sanger sequencing were employed to identity the pathogenic candidate gene. No translocation or microdeletion/duplication was found in karyotype analysis and array-CGH; hence, a novel heterozygous mutation, c.146dupA. p.S50Vfs*22, was detected by next-generation sequencing in PTHLH gene, leading to a premature stop codon. Subsequently, the mutation was confirmed by Sanger sequencing and co-segregation analysis. In this study, we described a novel heterozygous mutation (c.146dupA. p.S50Vfs*22) of gene PTHLH in a Chinese family. The mutation could induce a premature stop codon leading to a truncation of the protein. Our study broadened the mutation spectrum of PTHLH in BDE.

Variability and selection of tomato Sletr1-2 mutants backcross population to improve yield and fruit quality

Enhancing fruit quality and yield is the goal of creating superior tomato varieties. One area of concern for breeders is fruit shelf life. To produce better offspring, hybridization attempts to combine the traits of two parents, but the results can be unpredictable. Backcrossing can create stable offspring with desired traits and eliminate undesirable characteristics from the parent plants. This study aimed to assess the diversity among advanced backcross strains and to obtain backcross genotypes carrying mutant alleles that have a high level of similarity with the superior parental lines. The study was carried out from April to September 2019 at the Indonesian Vegetable Research Institute’s screen house. In this experiment, two populations of backcrossing comprised of commercial parents of ‘Intan’ and ‘Mutiara’ varieties as well as backcross genotypes including MBC3F1 32, MBC3F1 32.2, MBC3F1 32.3, MBC3F1 37.2, MBC3F1 45.3, MBC3F1 37.1, IBC3F1 34.2, IBC3F1 37.2, and IBC3F1 34 were utilized. A variance analysis was used to determine genotype diversity. The genetic similarity between parents and offspring was determined using cluster analysis, and a t-test was used to compare mean performance values. According to the results, the BC3F1 populations of ‘Intan’, and ‘Mutiara’ exhibited a high degree of phenotypic variability. Cluster analysis and a t-test revealed that the IBC3F1.37.2 and IBC3F1.45.3 genotypes resembled ‘Intan’, furthermore MBC3F1.34 and MBC3F1.34.2 had strikingly similar characteristics to ‘Mutiara’. Therefore, several individual plants carrying the Sletr1-2 mutant allele in these four genotypes can further assemble longer tomato fruit shelf life and high-yielding varieties.

EP133: Genome sequencing and chromosomal microarray as a tool for evaluating phenotypic variability in individuals with X and Y chromosome variations

Aneuploidies of the X and Y chromosomes (XXY and XYY) are characterized by a high degree of phenotypic variability, particularly in regard to neurodevelopment. Individuals with these diagnoses have varying neurocognitive presentations ranging from neurotypical to frank intellectual disability. The source of this variability is not yet well understood and phenotypic predictions cannot be made on an individual basis. One layer of this variance could be explained by the presence of high-impact Mendelian disorders that may be co-occurrent in this population.

Rapid signaling reactivation after targeted BRAF inhibition predicts the proliferation of individual melanoma cells from an isogenic population

Cancer cells within tumors display a high degree of phenotypic variability. This variability is thought to allow some of the cells to survive and persist after seemingly effective drug treatments. Studies on vemurafenib, a signaling inhibitor that targets an oncogenic BRAF mutation common in melanoma, suggested that cell-to-cell variation in drug resistance, measured by long-term proliferation, originates from epigenetic differences in gene expression that pre-exist treatment. However, it is still unknown whether reactivation of signaling downstream to the inhibited BRAF, thought to be a key step for resistance, is heterogeneous across cells. While previous studies established that signaling reactivation takes place many hours to days after treatment, they monitored reactivation with bulk-population assays unsuitable for detecting cell-to-cell heterogeneity. We hypothesized that signaling reactivation is heterogeneous and is almost instantaneous for a small subpopulation of resistant cells. We tested this hypothesis by monitoring signaling dynamics at a single-cell resolution and observed that despite highly uniform initial inhibition, roughly 15% of cells reactivated signaling within an hour of treatment. Moreover, by tracking cell lineages over multiple days, we established that these cells indeed proliferated more than neighboring cells, thus establishing that rapid signaling reactivation predicts long-term vemurafenib resistance.

Syndromic Inherited Retinal Diseases: Genetic, Clinical and Diagnostic Aspects.

Inherited retinal diseases (IRDs), which are among the most common genetic diseases in humans, define a clinically and genetically heterogeneous group of disorders. Over 80 forms of syndromic IRDs have been described. Approximately 200 genes are associated with these syndromes. The majority of syndromic IRDs are recessively inherited and rare. Many, although not all, syndromic IRDs can be classified into one of two major disease groups: inborn errors of metabolism and ciliopathies. Besides the retina, the systems and organs most commonly involved in syndromic IRDs are the central nervous system, ophthalmic extra-retinal tissues, ear, skeleton, kidney and the cardiovascular system. Due to the high degree of phenotypic variability and phenotypic overlap found in syndromic IRDs, correct diagnosis based on phenotypic features alone may be challenging and sometimes misleading. Therefore, genetic testing has become the benchmark for the diagnosis and management of patients with these conditions, as it complements the clinical findings and facilitates an accurate clinical diagnosis and treatment.

Hybrid forms of mandarin (Citrus reticulata blanco var. Unchiu tan.) from interspecific crosses and their characteristics

Representatives of the genus Citrus L., which includes C. limon, C. sinensis, C. reticulata, C. paradisi, C. maxima, C. medica, C. aurantifolia and other species are the most important fruit crops in countries with subtropical and tropical climates. Cross-pollination, variability of sexual offspring fixed by apomixis, preserved during vegetative propagation contributed to the appearance of intergeneric and interspecific hybrids combining characters and properties of different species. The aim of this work was to carry out interspecific crosses to create biodiversity of Citrus reticulata Blanco var. unchiu Tan. and create new forms with breeding valuable traits. Six interspecific combinations of crossings with the involvement of different varieties were carried out, and a large variety of seedlings was obtained. In sexual offspring from interspecific crosses, a high degree of phenotypic variability is observed on the leaf blade, in shape, size, color of the fruit, thickness and separability of the peel, the presence and absence of seeds, as well as organoleptic properties. All these characteristics represent important criteria for the variety. According to the totality of morphological characters, 24 promising forms were selected. The combination of C. reticulata × C. maxima crossing is the most productive, which allowed us to identify the largest number of forms with breeding valuable traits. Forms Yub - P Nmik; Yub – P Nmik - 1; MV - P Azah; MV - P Azah - 1; MV - P Azah - 2; Kr - P Azah; Cr - P Azah – 1 are promising and are important for the creation of new large-fruited varieties of mandarin. From combination of crossbreeding with C. sinensis such forms as KV - ApV, KV-ApV-2, MV-ApV-1were identified, characterized by large-fruited, fruits with high organoleptic properties. Hybrids bred with C. medica, C. aurantifolia, C. limon meyer are important for creating citrus biodiversity with valuable traits.

AGE VARIABILITY OF ETHOLOGICAL PARAMETERS OF CATTLE

It was found that ethological traits and indicators of milk production of cows are characterized by a medium and high degree of phenotypic variability. With age, cows rested less time lying down, but spent more time eating feed. Analyzing the factor depen

Plummer-Vinson Syndrome With Concomitant Factor VII Deficiency

Background: Plummer-Vinson syndrome (PVS), a rare disorder characterized by dysphagia, iron deficiency anemia, and esophageal webs, has principally been described in middle-aged women. This disorder is uncommon in the 21st century because of the abundance of iron-fortified foods. Clotting factor deficiencies are also rare. Factor VII deficiency is a bleeding disorder characterized by the absence of a critical protein in the coagulation cascade. Case Report: We present a case of PVS associated with factor VII deficiency in a 26-year-old African American female. The patient had a history of anemia that was repeatedly attributed to menstrual bleeding and dysphagia for 10 years. She presented with symptomatic anemia requiring transfusion. She reported a history of food getting stuck in her chest, and workup revealed esophageal webs with no evidence of overt luminal gastrointestinal bleeding. Coagulation laboratory tests revealed the incidental finding of a borderline increased prothrombin time. Hematologic studies confirmed the presence of factor VII deficiency. Conclusion: To our knowledge, no case has been published about a patient diagnosed with PVS and concomitant factor VII deficiency. Our case illustrates several learning points: (1) PVS is an uncommon disorder that may still be diagnosed in a developed country in the 21st century; (2) PVS requires close follow-up and esophageal surveillance because of the increased risk of esophageal cancer; (3) factor VII exhibits a high degree of phenotypic variability; (4) phenotype in factor VII deficiency does not always correlate with factor VII activity, although life-threatening spontaneous bleeding is not expected with levels >2%.

Phenotypic Variation of Cold Stress Resistance‐Related Traits of White Clover Populations Naturalized in Patagonian Cold Environments

White clover (Trifolium repens L.) is the main forage legume species in grazing pastures in central, central‐southern, and southern regions of Chile and many other temperate regions of the world. The selection of cold stress resistance genotypes is an important step for breeding cultivars to improve the clover growth curve and extend the grazing season in early spring and autumn. The objective of this work was to phenotypically characterize a population of 192 white clover genotypes selected for cold stress resistance under three contrasting regional winter‐cold conditions (mean daily minimum air temperatures of 2.5, 1.6, and −1.4°C) during the coldest month. An α‐lattice experimental field design was used, with 24 incomplete blocks and two replicates. Morphological, physiological and biochemical traits were evaluated at different dates over three growing seasons from 2013 to 2016. A high degree of variability was found among the genotypes for all the characteristics studied. There was no effect of environment when the experimental sites were considered as a source of variation, but comparison of measurements taken at dates separated by a winter showed that there was a decrease in stolon length and diameter, petiole length, leaflet size, and dry matter accumulation in response to cold conditions. The normalized difference and medium resolution imaging spectrometer terrestrial chlorophyll vegetation indices (NDVI and MTCI, respectively) and water‐soluble carbohydrate concentrations in stolons also varied among genotypes and were affected by winter cold. The high degree of phenotypic variability allows for the use of this population as a genetic source for cold stress resistance in white clover.

F39. Parsonage from a power tool: An unusual presentation of neuralgic amyotrophy in a 78 year old woman after using a chainsaw

Introduction A 78 year old Caucasian female presented for an electrodiagnostic (EDX) evaluation for right hand weakness and atrophy. Symptoms began 3 months prior one day after she was working with a chainsaw in the backyard and experienced severe right scapular pain followed by a monophasic course of progressively worsening weakness, inability to grip things such as a pen or coffee cup, and numbness and tingling into digits 1–3. Exam showed right sided prominent atrophy of the first dorsal interosseous (FDI) and thenar eminence, 4/5 strength in shoulder abduction and elbow flexion/extension, 3/5 strength in finger flexion and abduction, a positive okay sign, diminished sensation throughout the right upper limb. She also has weakness of the serratus anterior with mild medial winging of the right scapula during anteflexion. Myelogram and computed tomography showed no significant neural compression to explain patient’s symptoms, specifically no C8 compression. Methods The patient underwent EDX testing and a neuromuscular ultrasound. Results Nerve conduction studies showed prolonged distal onset latency and reduced amplitude of the right median motor nerve and no response in the right ulnar motor nerve, but were otherwise normal. Needle evaluation of the right FDI muscle showed reduced insertional activity with no recruitment of motor units, and the right pronator quadratus muscle showed reduced recruitment. Neuromuscular ultrasound of the right brachial plexus showed some increased hypoechogenicity and possible increased caliber compared to the left. The right forearm musculature including the pronator quadratus and FDI demonstrated increased hyperechogenicity and atrophy consistent with chronic denervation. Patient was diagnosed with a distal predominant neuralgic amyotrophy (NA) variant. Conclusion Neuralgic amyotrophy (NA), also known as Parsonage-Turner Syndrome, exhibits a high degree of phenotypic variability with only two-thirds of patients presenting with the classic phenotype with its predilection for the superior trunk of the brachial plexus. In this case, the patient met 5/5 of the clinical criteria for NA as defined by Van Alfen and neuromuscular ultrasound was helpful in further confirming the diagnosis. NA should be considered in patients even if they do not fit the classic phenotype of predominately proximal arm weakness and ultrasound of the plexus and affected muscles can be a helpful adjunctive diagnostic tool is such cases which do not “fit the textbook.”

Mutational screening of GLI3, SHH, preZRS, and ZRS in 102 Chinese children with nonsyndromic polydactyly.

Polydactyly is a group of congenital limb malformations that show high degree of phenotypic variability and genetic heterogeneity. In the present study, four genomic regions (exons of GLI3, SHH, and noncoding sequences of preZRS and ZRS) involved in hedgehog (Hh) signaling pathway were sequenced for 102 unrelated Chinese children with nonsyndromic polydactyly. Two GLI3 variants (c.2844 G > G/A; c.1486C > C/T) and four preZRS variants (chr7:156585336 A>G; chr7:156585421 C>A; chr7: 156585247 G>C; chr7:156585420 A > C) were observed in 2(2.0%) and 6(5.9%) patients, respectively. These variants are not over-represented in the Chinese healthy population. All the 8 cases showed preaxial polydactyly in hands. Additionally, no specific patterns of malformation predicted mutations in other candidate genes or sequences. This is the first report of the assessment of the frequency of GLI3/SHH/preZRS/ZRS in Chinese patients to show any higher possibility of mutations or variants for the 4 genes or sequences in China. Developmental Dynamics 246:392-402, 2017. © 2017 Wiley Periodicals, Inc.

Genotype/Phenotype Correlations in 103 Children from 87 Families with Hereditary Spherocytosis

Hereditary spherocytosis (HS) is the most common congenital hemolytic anemia in Caucasians. Patients with HS show a high degree of phenotypic variability from asymptomatic to transfusion dependence. Much of this variability stems from HS not being a single uniform disorder but instead being a collection of disorders involving mutations in 5 different genes (ANK1, SPTB, SPTA1, SLC4A1, and EPB42 ) encoding for the 5 major cytoskeletal proteins in red blood cells (ankyrin, β and α spectrin, band 3, and protein 4.2 respectively). These proteins are responsible for maintaining the biconcave disk morphology of red blood cells.Traditionally the diagnosis of HS has been made without genetic testing. We believe that knowledge of the HS subtype may impact future clinical management decisions, e.g. what type of splenectomy to perform-partial vs total and impact on genetic counseling needs. As a result we are now pursuing genetic testing on all our patients with HS.Over the past 16 years at Sick Kids Hospital (Toronto, Canada), we have followed 257 children with HS. In the past year we have also been offering genetic testing (following informed consent) to all children (<18 years old) still being followed in our center. DNA is sent to Prevention Genetics (Wisconsin, USA) where Next Generation sequencing is performed. Mutations are verified by Sanger sequencing.In total, we have genetic test results on 103 children from 87 families to date. Mutations in ANK1 were most common (50 children/43 families); followed by mutations in SPTB (32 children/26 families); SLC4A1 (7 children/7 families) and finally SPTA1 (6 children/3 families) EPB42 mutations were not found to be causative for HS in our cohort. In 8 children (8 families) no causative mutation for HS was found. In 23% of children multiple mutations were found -particularly heterozygous mutations of SPTA1 in combination with ANK1 or SPTB mutations.The majority of mutations in our patients were nonsense, frameshift, or splice site mutations. Most were novel - not previously described mutations, and unique to families. There were 5 exceptions to this; 1) c.4339-99C>T in SPTA1 (referred to as the αLEPRA mutation) in 4 children/2 families with an α spectrin form of HS, and in another 2 children (1 family) with an ankyrin form of HS; 2) an ANK1 c.5097-33G>A (8 children/6 families); 3) an ANK1 c.1405-9G>A (4 children/3 families); 4) SPTB c.6037C>T (3 children/2 families); and 5) SPTB c.5266C>T (3 children/2 families). The ANK1 c.5097-33G>A mutation had not been previously identified and yet was the most frequently detected mutation in our HS population.Most children (68/103) were found to have autosomal dominant (AD) HS: 33 children with the ankyrin subtype, 26 with the β spectrin subtype, 4 with the band 3 subtype and 5 in whom no mutation could be found but where there was a clear history of AD inheritance. Autosomal recessive (AR) inheritance was confirmed in 7 children - all 6 with α spectrin form of HS and 1 with a β spectrin form of HS. Twenty-eight children were spontaneous new mutations for HS: ANK (n=17), β spectrin (n=5), band 3 (n=3) and 3 in whom no mutation could be found. In all AR forms of HS, the index case had initially been thought to be a spontaneous new mutation for an AD form of HS; genetic testing resolved the inheritance pattern.Patients were categorized according to disease severity, primarily on the basis of their need for transfusions (a reflection of baseline hemoglobin) and splenectomy. The proportion of children that have required transfusions and needed splenectomies was: 83%/83% (α spectrin); 48%/18% (ankyrin), 23%/10% (β spectrin) and 29%/0% (band 3).Most children in our center undergoing splenectomy have undergone partial splenectomy; few have required subsequent total splenectomy. However, of the 5/6 children with α spectrin form of HS that underwent partial splenectomy 3 have subsequently needed, or are being considered for, total splenectomy. This suggests that due to the extreme severity of the α spectrin subtype of HS, children with this form of HS may not do well long-term with partial splenectomy and are likely to eventually require a total splenectomy.Our study to date represents one of the largest and most comprehensive genetic analyses of a cohort of HS patients. Our findings will add to the growing understanding of the disease, and will be important to provide comprehensive genetic counseling and possibly in the future to guide management of selected cases. DisclosuresDrury:Prevention Genetics: Employment.

Effectiveness of a computer vision technique in the characterization of wild and farmed olives

Existing in two forms, namely the wild and the cultivated one, the olive tree (Olea europaea L.) is one of the most widespread species in the Mediterranean Basin since the sixth millennium B.C. According to the theory of a polycentric origin for domestication, mainly supported by the presence of the wild form all over the Mediterranean area, the goal of this study is to use endocarps biometric features, measured by image analysis techniques, in order to investigate the relationships among different Sardinian wild olive populations, ancient olive trees and olive cultivars. A total of 137 morphometric, colorimetric and textural characters were measured on each of the 2842 studied endocarps. The morpho-colorimetric analysis of olive endocarps proved the effectiveness of the technique to discriminate between the two currently recognized O. europaea L. varieties (var. europaea and var. sylvestris). The partial overlapping that resulted between wild and ancient olives suggests the existence of large populations characterized by a high degree of phenotypic variability. Similar results were reached for varietal discrimination, perfectly fitting with previous findings of molecular studies. Considering the phenotypic and genetic distance of cultivars from autochthonous wild olives, the allochthonous origin of local varieties is furthermore confirmed.

Phenotypic heterogeneity and temporal expression of the capsular polysaccharide in Staphylococcus aureus.

Bacteria respond to ever-changing environments through several adaptive strategies. This includes mechanisms leading to a high degree of phenotypic variability within a genetically homogeneous population. In Staphylococcus aureus, the capsular polysaccharide (CP) protects against phagocytosis, but also impedes adherence to endothelial cells and/or matrix proteins. We analysed the regulation of core biosynthesis genes (capA-P) necessary for CP synthesis using single-cell assays (immunofluorescence and promoter-activity). In persistent human carriers, we found a distinct subpopulation of nasal S. aureus to be CP positive. In vitro, cap expression is also heterogeneous and strongly growth-phase dependent. We asked whether this peculiar expression pattern (earlyOff/lateHeterogen) is orchestrated by the quorum system Agr. We show that the Agr-driven effector molecule RNAIII promotes cap expression largely via inactivation of the repressor Rot. High NaCl, deletion of CodY or Sae also resulted in higher cap expression but did not change the earlyOFF/lateHeterogen expression pattern. Activity of the quorum system itself is largely homogenous and does not account for the observed heterogeneity of cap expression or the strictly growth phase dependent expression. Our findings are in contrast to the prevailing view that quorum sensing is the main driving force for virulence gene expression when bacterial cell densities increase.

CE: Nursing Management of Patients with Ehlers-Danlos Syndrome.

Ehlers-Danlos syndrome (EDS), a hereditary connective tissue disorder, has historically been misunderstood and underdiagnosed by health care providers. Because of the high degree of phenotypic variability, patients are often correctly diagnosed only after years of seemingly unrelated but debilitating injuries and illnesses. Specific genetic mutations have been identified for some, but not all, EDS types; patients presenting with a high index of suspicion should be referred to a geneticist. As awareness and recognition of the syndrome improve, nurses are increasingly likely to care for patients with EDS. This article gives a brief overview of the syndrome and provides guidance on ways to manage symptoms, recognize and prevent serious complications, and improve patients' quality of life.

Exome sequencing reveals a novel PTHLH mutation in a Chinese pedigree with brachydactyly type E and short stature

Brachydactyly includes shortening of digits due to abnormal development of phalanges, metacarpals, or both. It can occur either as an isolated malformation or with other anomalies as part of many congenital syndromes. It is included as one of the dysostosis groups affecting the limbs in the nosology and classification of genetic skeletal disorders. However, brachydactyly usually shows a high degree of phenotypic variability. In this study, we successfully identified a novel heterozygous mutation of the parathyroid hormone-like hormone (PTHLH) gene by exome sequencing in a Chinese pedigree with brachydactyly and short stature. The PTHLH gene encodes a parathyroid hormone-related protein (PTHrP) that is involved in the regulation of endochondral bone development, and mutations in this gene cause the type E form of brachydactyly. The mutation p.L15R occurs at a hydrophobic core region of the signal peptide, suggesting that this variation probably changes the signal peptide cleavage site at the in silico prediction. Further in vitro functional analysis showed that this mutation can lead to the retention of an N-terminal signal peptide fragment after the nascent proteins are translated.

The Y141C knockin mutation in RDS leads to complex phenotypes in the mouse.

Mutations in the photoreceptor-specific gene peripherin-2 (PRPH-2, also known as retinal degeneration slow/RDS) cause incurable retinal degeneration with a high degree of phenotypic variability. Patient phenotypes range from retinitis pigmentosa to various forms of macular and pattern dystrophy. Macular and pattern dystrophy in particular are associated with complex, poorly understood disease mechanisms, as severe vision loss is often associated both with defects in the photoreceptors, as well as the choroid and retinal pigment epithelium (RPE). Since there is currently no satisfactory model to study pattern dystrophy disease mechanisms, we generated a knockin mouse model expressing an RDS pattern dystrophy mutation, Y141C. Y141C mice exhibited clinical signs similar to those in patients including late-onset fundus abnormalities characteristic of RPE and choroidal defects and electroretinogram defects. Ultrastructural examination indicated that disc formation was initiated by the Y141C protein, but proper sizing and alignment of discs required wild-type RDS. The biochemical mechanism underlying these abnormalities was tied to defects in the normal process of RDS oligomerization which is required for proper RDS function. Y141C-RDS formed strikingly abnormal disulfide-linked complexes which were localized to the outer segment (OS) where they impaired the formation of proper OS structure. These data support a model of pattern dystrophy wherein a primary molecular defect occurring in all photoreceptors leads to secondary sequellae in adjacent tissues, an outcome which leads to macular vision loss. An understanding of the role of RDS in the interplay between these tissues significantly enhances our understanding of RDS-associated pathobiology and our ability to design rational treatment strategies.

Chromosomal instability and molecular mutations in multi spectrum disease of Fanconi anemia

Fanconi anemia (FA; MIM no. 227650), the most commonly inherited bone marrow disorder, has an overall prevalence of 1–5 per million and an estimated carrier frequency of 1:200-300 in most populations. Demonstrating either an autosomal or X-linked recessive mode of inheritance, FA is characterized by childhood progressive bone marrow failure and predisposition to acute myelogenous leukemia, older patients are at increased risk for squamous cell carcinomas of the head, neck, and genitourinary tract. Congenital abnormalities are present in approximately 70% of FA patients and may include radial ray defects, cafe´ au lait spots or hypopigmentation, short stature, microphthalmia, malformations of kidneys, gastrointestinal tract, and heart, mental retardation, and hearing defects. Because of the high degree of phenotypic variability exhibited by FA patients, diagnosis may be difficult on the basis of clinical manifestations alone. Because FA patient-derived lymphocytes and fibroblasts exhibit hypersensitivity to DNA crosslinking agents such as diepoxybutane (DEB) and mitomycin C (MMC), resulting in a high rate of chromosomal breakage and radial formation, analysis on the basis of this hypersensitivity has been routinely used to confirm clinical diagnosis. Molecular diagnosis of FA has been challenging because of the genetic heterogeneity associated with the disease. To date, 15 FA gene products (FANCA, B, C, D1, D2, E, F, G, I, J, L, M, N, O and P) have been identified and they constitute the FANC pathway, which is thought to function in preventing genome instability. The FA core complex comprises FAAP24, FAAP100, and 8 FA proteins (FANCA, B, C, E, F, G, L, and M) and mediates DNA-damage-induced or replication-stress induced monoubiquitylation of FANCD2 and FANCI. Monoubiquitinated FANCD2 and FANCI translocate to chromatin and function in DNA repair at least partially by recruitment of FAN1 nuclease. Cloning of the FANC genes has provided a means, via complementation group analysis, to routinely pinpoint the patient’s specific FA gene harboring the mutations, thus greatly simplifying subsequent molecular analysis. Although retroviral-mediated complementation analysis of FA patient-derived cells is commonly used to identify the patient’s genetic subtype as a prerequisite for mutation screening, such analysis has not been formally validated for clinical use. Previous studies have considered Fanconi complementation Group A (FA-A) assignments, but none have performed comprehensive sequencing to verify complementation assignment and/or evaluated complementation assignments performed using retroviral-mediated rescue as evidenced by correction of MMC and DEB-induced chromosome breakage and radial formation. Among all complementation groups, FAA accounts for the majority of FA patients (60–65%) followed by FAC (10%) and FAG (9%). Mutations in the gene for complementation group FA-A (FANCA; MIM no. 607139) confer autosomal recessive inheritance and account for approximately 66% of all FA cases. The FANCA gene is mapped to chromosome 16q24.3,11 spans approximately 80 kb of genomic DNA (gDNA), and consists of 43 exons. With more than 200 different mutations described thus far, the FANCA mutation spectrum is very heterogeneous. Because of the presence of a large number of Alu repeat sequences within the FANCA gene, large intragenic deletions involving multiple exons have been reported to account for more than 40% of all FANCA mutations. First time we have carried out a molecular study in the Indian population. We have studied FA by chromosomal breakage study using mitomycin C (MMC) and diepoxybutane (DEB) induction and FANCD2 monoubiquitination by western blotting to understand gene defects in FA pathway. The complementation analysis was done by retroviral transfection. The molecular study was carried out by Multiplex Ligation-dependent Probe Amplification (MLPA) and direct sequencing of FANCA, C, G, E, F, L, and M genes. The complementation analysis results showed different spectrum as compared to world literature. Our study revealed FA-A and E gene defects in 69% cases and followed by FANCE gene defect. The molecular analysis showed the large deletions in 11 patients and FANCA gene mutations were in 12 FA patients. Out of 12 mutations 5 mutations (c.3678 C>G, p.Ser 1226 X, c.3993G>A p.Leu 1331 Pro, c.1274 C>G p.Glu 425 His, c.2630 C>G p.Ser 877 X) found to be novel mutations. In our series the single nucleotide polymorphisms (SNP); Exon9,c.796A>G(p.Thr266Ala), Exon16,c.1501G>A(p.Gly501Ser), Exon26, c.2426G>A(p.Gly809Asp), of FANCA gene also observed in 23 patients, and these polymorphisms in disease association was reported in FA database, however, it needs to be established in Indian population. Interesting finding of our study is the existence of FANCE mutation in Indian population, and the same was reported rarely in other places of the world. The study also highlighted the uncharacterized FA patients, which may associated with new genes in Indian population and these patients should be studied molecularly and genotype-phenotype correlation need to be established, which helps in better understanding and management of the disease.

Brachydactyly E: isolated or as a feature of a syndrome

Brachydactyly (BD) refers to the shortening of the hands, feet or both. There are different types of BD; among them, type E (BDE) is a rare type that can present as an isolated feature or as part of more complex syndromes, such as: pseudohypopthyroidism (PHP), hypertension with BD or Bilginturan BD (HTNB), BD with mental retardation (BDMR) or BDE with short stature, PTHLH type. Each syndrome has characteristic patterns of skeletal involvement. However, brachydactyly is not a constant feature and shows a high degree of phenotypic variability. In addition, there are other syndromes that can be misdiagnosed as brachydactyly type E, some of which will also be discussed. The objective of this review is to describe some of the syndromes in which BDE is present, focusing on clinical, biochemical and genetic characteristics as features of differential diagnoses, with the aim of establishing an algorithm for their differential diagnosis. As in our experience many of these patients are recruited at Endocrinology and/or Pediatric Endocrinology Services due to their short stature, we have focused the algorithm in those steps that could mainly help these professionals.

Individual Phenotypic Variances in a Family With Thiel–Behnke Corneal Dystrophy

To diagnose Thiel-Behnke dystrophy, an autosomal dominant disease of the anterior basement membrane/Bowman membrane complex and corneal stroma, currently relies primarily on the overall clinical presentation of patient complaints, inheritance pattern, and physical appearance of the corneal findings on slit-lamp examination. Key challenges to accurately identifying the disease are variable and often obscured morphology caused from secondary scarring, creating phenotypic deviation from the "classical" presentation, and mimicry of characteristics typical of other closely related dystrophies. In this report, we demonstrate the high degree of phenotypic variability that can be found in this disease. A well-characterized family with an established diagnosis of Thiel-Behnke dystrophy mapped to chromosome 10 was evaluated along with the corresponding pedigree. Each individual was examined under slit lamp, and any apparent lesions were photographed. In total, 4 generations were represented with 20 affected members accounted for, ranging from ages 11 to 86 years. We observed 4 phenotypes in this family: (1) the majority displayed "honeycomb" reticular opacities consistent with Thiel-Behnke dystrophy, (2) several subjects showed more granular-like deposits in a geographic distribution, (3) younger subjects with possible early manifestations of the disease possessed small superficial vesicles, and (4) some eyes exhibited an intermediate form with 2 distinct disease presentations at different regions within the same cornea. Taken together, the pedigree demonstrated a wide continuous spectrum of phenotypes from a supposedly singular genetic disorder that may also vary based on the age of patient. These observations show that the clinical phenotypic appearance alone can result in a variety of different and conflicting diagnoses. With such potential for error, improvement in the diagnostic criteria is necessary.