Genetic Profiling of Sodium Channels in Diabetic Painful and Painless and Idiopathic Painful and Painless Neuropathies.

Neuropathic pain is a frequent feature of diabetic peripheral neuropathy (DPN) and small fiber neuropathy (SFN). Resolving the genetic architecture of these painful neuropathies will lead to better disease management strategies, counselling and intervention. Our aims were to profile ten sodium channel genes (SCG) expressed in a nociceptive pathway in painful and painless DPN and painful and painless SFN patients, and to provide a perspective for clinicians who assess patients with painful peripheral neuropathy. Between June 2014 and September 2016, 1125 patients with painful-DPN (n = 237), painless-DPN (n = 309), painful-SFN (n = 547) and painless-SFN (n = 32), recruited in four different centers, were analyzed for SCN3A, SCN7A-SCN11A and SCN1B-SCN4B variants by single molecule Molecular inversion probes-Next Generation Sequence. Patients were grouped based on phenotype and the presence of SCG variants. Screening of SCN3A, SCN7A-SCN11A, and SCN1B-SCN4B revealed 125 different (potential) pathogenic variants in 194 patients (17.2%, n = 194/1125). A potential pathogenic variant was present in 18.1% (n = 142/784) of painful neuropathy patients vs. 15.2% (n = 52/341) of painless neuropathy patients (17.3% (n = 41/237) for painful-DPN patients, 14.9% (n = 46/309) for painless-DPN patients, 18.5% (n = 101/547) for painful-SFN patients, and 18.8% (n = 6/32) for painless-SFN patients). Of the variants detected, 70% were in SCN7A, SCN9A, SCN10A and SCN11A. The frequency of SCN9A and SCN11A variants was the highest in painful-SFN patients, SCN7A variants in painful-DPN patients, and SCN10A variants in painless-DPN patients. Our findings suggest that rare SCG genetic variants may contribute to the development of painful neuropathy. Genetic profiling and SCG variant identification should aid in a better understanding of the genetic variability in patients with painful and painless neuropathy, and may lead to better risk stratification and the development of more targeted and personalized pain treatments.

Peripheral Ion Channel Genes Screening in Painful Small Fiber Neuropathy.

Neuropathic pain is a characteristic feature of small fiber neuropathy (SFN), which in 18% of the cases is caused by genetic variants in voltage-gated sodium ion channels. In this study, we assessed the role of fifteen other ion channels in neuropathic pain. Patients with SFN (n = 414) were analyzed for ANO1, ANO3, HCN1, KCNA2, KCNA4, KCNK18, KCNN1, KCNQ3, KCNQ5, KCNS1, TRPA1, TRPM8, TRPV1, TRPV3 and TRPV4 variants by single-molecule molecular inversion probes-next-generation sequencing. These patients did not have genetic variants in SCN3A, SCN7A-SCN11A and SCN1B-SCN4B. In twenty patients (20/414, 4.8%), a potentially pathogenic heterozygous variant was identified in an ion-channel gene (ICG). Variants were present in seven genes, for two patients (0.5%) in ANO3, one (0.2%) in KCNK18, two (0.5%) in KCNQ3, seven (1.7%) in TRPA1, three (0.7%) in TRPM8, three (0.7%) in TRPV1 and two (0.5%) in TRPV3. Variants in the TRP genes were the most frequent (n = 15, 3.6%), partly in patients with high mean maximal pain scores VAS = 9.65 ± 0.7 (n = 4). Patients with ICG variants reported more severe pain compared to patients without such variants (VAS = 9.36 ± 0.72 vs. VAS = 7.47 ± 2.37). This cohort study identified ICG variants in neuropathic pain in SFN, complementing previous findings of ICG variants in diabetic neuropathy. These data show that ICG variants are central in neuropathic pain of different etiologies and provides promising gene candidates for future research.

Peripheral Ion Channel Gene Screening in Painful- and Painless-Diabetic Neuropathy.

Neuropathic pain is common in diabetic peripheral neuropathy (DN), probably caused by pathogenic ion channel gene variants. Therefore, we performed molecular inversion probes-next generation sequencing of 5 transient receptor potential cation channels, 8 potassium channels and 2 calcium-activated chloride channel genes in 222 painful- and 304 painless-DN patients. Twelve painful-DN (5.4%) patients showed potentially pathogenic variants (five nonsense/frameshift, seven missense, one out-of-frame deletion) in ANO3 (n = 3), HCN1 (n = 1), KCNK18 (n = 2), TRPA1 (n = 3), TRPM8 (n = 3) and TRPV4 (n = 1) and fourteen painless-DN patients (4.6%-three nonsense/frameshift, nine missense, one out-of-frame deletion) in ANO1 (n = 1), KCNK18 (n = 3), KCNQ3 (n = 1), TRPA1 (n = 2), TRPM8 (n = 1), TRPV1 (n = 3) and TRPV4 (n = 3). Missense variants were present in both conditions, presumably with loss- or gain-of-functions. KCNK18 nonsense/frameshift variants were found in painless/painful-DN, making a causal role in pain less likely. Surprisingly, premature stop-codons with likely nonsense-mediated RNA-decay were more frequent in painful-DN. Although limited in number, painful-DN patients with ion channel gene variants reported higher maximal pain during the night and day. Moreover, painful-DN patients with TRP variants had abnormal thermal thresholds and more severe pain during the night and day. Our results suggest a role of ion channel gene variants in neuropathic pain, but functional validation is required.

A novel gain-of-function sodium channel ß2 subunit mutation in idiopathic small fiber neuropathy.

Small fiber neuropathy (SFN) is a common condition affecting thinly myelinated Aδ and unmyelinated C fibers, often resulting in excruciating pain and dysautonomia. SFN has been associated with several conditions, but a significant number of cases have no discernible cause. Recent genetic studies have identified potentially pathogenic gain-of-function mutations in several pore-forming voltage-gated sodium channel α subunits (NaV) in a subset of patients with SFN, but the auxiliary sodium channel ß subunits have been less implicated in the development of the disease. ß subunits modulate NaV trafficking and gating, and several mutations have been linked to epilepsy and cardiac dysfunction. Recently, we provided the first evidence for the contribution of a mutation in the ß2 subunit to pain in human painful diabetic neuropathy. Here, we provide the first evidence for the involvement of a sodium channel ß subunit mutation in the pathogenesis of SFN with no other known causes. We show, through current-clamp analysis, that the newly identified Y69H variant of the ß2 subunit induces neuronal hyperexcitability in dorsal root ganglion neurons, lowering the threshold for action potential firing and allowing for increased repetitive action potential spiking. Underlying the hyperexcitability induced by the ß2-Y69H variant, we demonstrate an upregulation in tetrodotoxin-sensitive, but not tetrodotoxin-resistant sodium currents. This provides the first evidence for the involvement of ß2 subunits in SFN and strengthens the link between sodium channel ß subunits and the development of neuropathic pain in humans.NEW & NOTEWORTHY Small fiber neuropathy (SFN) often has no discernible cause, although mutations in the voltage-gated sodium channel α subunits have been implicated in some cases. We identify a patient suffering from SFN with a mutation in the auxiliary ß2 subunit and no other discernible causes for SFN. Functional assessment confirms this mutation renders dorsal root ganglion neurons hyperexcitable and upregulates tetrodotoxin-sensitive sodium currents. This study strengthens a newly emerging link between sodium channel ß2 subunit mutations and human pain disorders.

TIMAP Upregulation Correlates Negatively with Survival in HER2- Negative Subtypes of Breast Cancer.

OBJECTIVE: TIMAP expression is regulated by transforming growth factor beta 1 (TGFß1); known for its role in breast cancer development and metastasis. Nevertheless, data on TIMAP protein expression and its association with breast cancer development are lacking. In this study, we aimed to investigate the variation in TIMAP protein expression in breast cancer tissue and its correlation with various clinicopathological characteristics of breast cancer patients and overall survival rate. METHODS: A total of 159 paraffin-embedded tissue blocks from women diagnosed with four breast cancer subtypes (49 HER2-only, 33 Luminal A, 39 Luminal B, and 38 triple negative) were used to construct tissue microarray (TMA), followed by TIMAP immunohistochemistry (IHC). TIMAP expression was scored by two pathologists and categorized as weak (1-33% expression), moderate (34-66%), and strong (67-100%). Chi-square test and Kaplan Meier survival test were performed to determine the association between TIMAP expression and clinicopathological features and overall survival rate, respectively. RESULTS: TIMAP protein was strongly expressed in 46 (93.9%) HER2-only, 32 (97%) luminal A, 37 (94.9%) luminal B, and 29 (76.3%) triple negative. TIMAP expression negatively associated with ER/PR expression (P=0.03), and it negatively impacted the overall survival in HER2 negative group (P=0.02). CONCLUSION: Our findings suggest that TIMAP protein expression is upregulated in all breast cancer subtypes. However, its prognostic role is exclusively observed in HER2- negative group, suggesting a potential of targeting TIMAP in future therapeutic strategies in this group.

Correction: Evaluation of molecular inversion probe versus TruSeq® custom methods for targeted next-generation sequencing.

[This corrects the article DOI: 10.1371/journal.pone.0238467.].

Hereditary multiple osteochondromas in Jordanian patients: Mutational and immunohistochemical analysis of EXT1 and EXT2 genes.

The aim of the present study was to investigate the molecular characteristics of hereditary multiple osteochondromas (HMO) in a subset of Jordanian patients with a focus on the genetic variants of exostosin (EXT1)/(EXT2) and their protein expression. Patients with HMO and their family members were included. Recorded clinical characteristics included age, sex, tumors number and location, joint deformities and associated functional limitations. Mutational analysis of EXT1 and EXT2 exonic regions was performed. Immunohistochemical staining for EXT1 and EXT2 was performed manually using two different commercially available rabbit anti-human EXT1 and EXT2 antibodies. A total of 16 patients with HMO from nine unrelated families were included, with a mean age of 13.9 years. A total of 75% (12/16) of the patients were male and (69%) (11/16) had a mild disease (class I). EXT mutation analysis revealed only EXT1 gene mutations in 13 patients. Seven variants were detected, among which three were novel: c.1019G>A, p. (Arg340His), c.962+1G>A and c.1469del, p. (Leu490Argfs*9). Of the 16 patients, 3 did not harbor any mutations for either EXT1 or EXT2. Immunohistochemical examination revealed decreased expression of EXT1 protein in all patients with EXT1 mutation. Surprisingly, EXT2 protein was not detected in these patients, although none had EXT2 mutations. The majority of Jordanian patients with HMO, who may represent an ethnic group that is infrequently investigated, were males and had a mild clinical disease course; whereas most patients with EXT1 gene mutations were not necessarily associated with a severe clinical disease course. The role of EXT2 gene remains a subject of debate, since patients with EXT1 mutations alone did not express the non-mutated EXT2 gene.

Elevated interleukin 31 serum levels in hemodialysis patients are associated with uremic pruritus.

INTRODUCTION: Uremic pruritus is a multifactorial devastating complication of renal failure, which has a significant negative impact on patients' quality of life including medical, psychological, as well as social aspects. It is also associated with an increased mortality in dialysis patients. METHODS: A cross sectional study evaluating the traditional risk factors for uremic pruritus (UP) - using pruritus grading system (PGS) and visual analogue scale (VAS) - as well as measuring the serum levels of different inflammatory cytokines (ILs 13, 31 and 33) in chronic hemodialysis and healthy controls, in a tertiary referral hospital. RESULTS: 65 hemodialysis (HD) patients and 49 heathy controls were enrolled in the study. The mean age for the HD patients was 43.4 years (SD ± 21.3), and 31.5 years (SD ± 11.1) for the control group. The most common cause for End Stage Renal Disease (ESRD) was diabetes mellitus (DM) 27.7%. The mean PGS score in HD patients was 5.92 (SD ± 2.9); 50% had mild itch, 43.8% moderate itch and 6.2% had severe itch. The mean serum levels for IL-13 was 8674.3 pg/ml (SD ± 4353.9), serum levels of IL-31 were 150.7 pg/ml (SD ± 178.2) and for IL-33 it was 42850.5 pg/ml (SD ± 11370.7) in hemodialysis patients; in comparison to serum levels of 7913.4 pg/ml (SD ± 3454.1), 67.1 pg/ml (SD ± 71.9) and 44875.9 pg/ml (SD ± 12114.6), respectively in the control group. IL-31 level was significantly higher in HD patients than in the control group (P = 0.0001), while the difference in the levels of IL-13 and IL-33 between the two groups were not statistically significant (P = 0.41 and 0.18, respectively). IL-13 had a statistically significant relationship with the itch score (P = 0.014) and the severity of itch (P = 0.03), while IL-31 and IL-33 were not statistically significant. CONCLUSION: UP is a complex and multifactorial problem. In patients with UP the high levels of IL-31 indicates a possible role in pathogenesis. IL-13 serum level on the other hand may be related to the severity of itch in these patients. Optimizing dialysis and targeting these cytokines may provide a potential therapeutic option especially in refractory UP. Further studies addressing these cytokines and their levels in response to various treatments may provide additional information on UP.

Evaluation of molecular inversion probe versus TruSeq® custom methods for targeted next-generation sequencing.

Resolving the genetic architecture of painful neuropathy will lead to better disease management strategies. We aimed to develop a reliable method to re-sequence multiple genes in a large cohort of painful neuropathy patients at low cost. In this study, we compared sensitivity, specificity, targeting efficiency, performance and cost effectiveness of Molecular Inversion Probes-Next generation sequencing (MIPs-NGS) and TruSeq® Custom Amplicon-Next generation sequencing (TSCA-NGS). Capture probes were designed to target nine sodium channel genes (SCN3A, SCN8A-SCN11A, and SCN1B-SCN4B). One hundred sixty-six patients with diabetic and idiopathic neuropathy were tested by both methods, 70 patients were validated by Sanger sequencing. Sensitivity, specificity and performance of both techniques were comparable, and in agreement with Sanger sequencing. The average targeted regions coverage for MIPs-NGS was 97.3% versus 93.9% for TSCA-NGS. MIPs-NGS has a more versatile assay design and is more flexible than TSCA-NGS. The cost of MIPs-NGS is >5 times cheaper than TSCA-NGS when 500 or more samples are tested. In conclusion, MIPs-NGS is a reliable, flexible, and relatively inexpensive method to detect genetic variations in a large cohort of patients. In our centers, MIPs-NGS is currently implemented as a routine diagnostic tool for screening of sodium channel genes in painful neuropathy patients.

IL-33/13 Axis and IL-4/31 Axis Play Distinct Roles in Inflammatory Process and Itch in Psoriasis and Atopic Dermatitis.

BACKGROUND: Pruritus is the most common symptom in patients with skin disease. Psoriasis and atopic dermatitis are clinically distinct inflammatory diseases. Interleukins are cytokines which play key roles in inflammatory signaling pathways. MATERIALS AND METHODS: Cross-sectional study was conducted among patients with psoriasis and atopic dermatitis: 59 psoriatic patients, 56 AD patients, and 49 matched healthy controls. Interleukins 4, 13, 31, 33 serum levels were assayed by ELISA and results were compared using SPSS. Itch severity and disease severity were measured and correlation with interleukin levels was determined using SPSS. RESULTS: The serum levels of IL-4, -13, -31, -33 were elevated in atopic dermatitis patients compared to controls. Itch and disease severity were not correlated with elevated serum levels of these interleukins. In psoriasis, the levels of IL-4 and -31 were elevated compared to controls, whereas the levels of IL-13 and -33 were lower than controls. The levels of measured interleukins in psoriasis did not correlate with itch and disease severity. CONCLUSION: IL-31 is the key mediator for pruritus in both AD and Ps patients. IL-4/31 axis and IL-33/13 axis play distinct roles in the pathogenesis of Atopic dermatitis and Psoriasis. Interleukin serum levels were not correlated with itch and disease severity in both conditions.

LAT1 (SLC7A5) Overexpression in Negative Her2 Group of Breast Cancer: A Potential Therapy Target.

OBJECTIVE: HER2 negative carcinomas of the breast pose a challenge for treatment due to redundancies in potential drug targets and poor patient outcomes. Our aim was to investigate the role of L-type amino acid transporter - LAT1 as a potential prognosticator and a drug target. METHODS: In this retrospective work, we have studied the expression of LAT1 in 145 breast cancer tissues via immunohistochemistry. Overall survival analysis was used to evaluate patient outcome in various groups of our cohort. RESULTS: Positive LAT1 expression was found in 27 (84.4%) luminal A subtype, 27 (64.3%) luminal B/triple positive subtype, 29 (82.9%) triple negative subtype, and 24 (66.7%) HER2-only positive subtype (p=0.1). Interestingly, negative correlation was found between LAT1 and HER2; where positive expression of LAT1 was found in 56 (83.6%) cases in negative HER2 group and 51 (65.4%) cases from positive HER2 group (p=0.01). Unfortunately, we were unable to report significant survival differences when LAT1 expression was studied in the negative HER2 group. Nevertheless, five incidents of mortality (out of 55) were reported in LAT1+/HER2- group compared to none in the LAT1-/HER2- group (N=11). CONCLUSION: Our findings of overexpression of LAT1 in negative HER2 group suggest a role of this protein as prognosticator and drug target in a challenging therapeutic cohort.
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Homozygous damaging SOD2 variant causes lethal neonatal dilated cardiomyopathy.

BACKGROUND: Idiopathic dilated cardiomyopathy (DCM) is recognised to be a heritable disorder, yet clinical genetic testing does not produce a diagnosis in >50% of paediatric patients. Identifying a genetic cause is crucial because this knowledge can affect management options, cardiac surveillance in relatives and reproductive decision-making. In this study, we sought to identify the underlying genetic defect in a patient born to consanguineous parents with rapidly progressive DCM that led to death in early infancy. METHODS AND RESULTS: Exome sequencing revealed a potentially pathogenic, homozygous missense variant, c.542G>T, p.(Gly181Val), in SOD2. This gene encodes superoxide dismutase 2 (SOD2) or manganese-superoxide dismutase, a mitochondrial matrix protein that scavenges oxygen radicals produced by oxidation-reduction and electron transport reactions occurring in mitochondria via conversion of superoxide anion (O2-·) into H2O2. Measurement of hydroethidine oxidation showed a significant increase in O2-· levels in the patient's skin fibroblasts, as compared with controls, and this was paralleled by reduced catalytic activity of SOD2 in patient fibroblasts and muscle. Lentiviral complementation experiments demonstrated that mitochondrial SOD2 activity could be completely restored on transduction with wild type SOD2. CONCLUSION: Our results provide evidence that defective SOD2 may lead to toxic increases in the levels of damaging oxygen radicals in the neonatal heart, which can result in rapidly developing heart failure and death. We propose SOD2 as a novel nuclear-encoded mitochondrial protein involved in severe human neonatal cardiomyopathy, thus expanding the wide range of genetic factors involved in paediatric cardiomyopathies.

Evaluation of Patched-1 Protein Expression Level in Low Risk and High Risk Basal Cell Carcinoma Subtypes.

Objective: Basal cell carcinoma (BCC) is the most common malignancy in humans and represents a growing public health care problem. The major etiological factors contributing to BCC development are exposure to ultraviolet radiation and genetic alterations. BCC is primarily caused by dysregulation of sonic Hedgehog (HH) signaling pathway in basal cells of the skin. BCC can be classified into low risk non-aggressive and high risk aggressive subtypes. BCC subtypes differentiation is essential for prognosis and for better disease management and treatment strategies. The aim of this study was to assess the correlation between PTCH1 protein expression level and the aggressiveness of BCC histopathology. Methods: Archival paraffin embedded blocks containing BCC were retrieved from a cohort of 101 patients. Immunohistochemistry staining was performed to assess the expression level of PTCH1 which is a key component of Hedgehog pathway. Results: 101 paraffin embedded samples were evaluated and classified as high risk and low risk BCC subtypes by histopathological finding. High risk BCC subtypes were found in 40 samples (39.6%) and low risk subtypes were identified in 61 samples (60.4%). Nodular was the most frequent subtype which was found in (56/ 101), followed by infiltrative (22/101) and micronodular (14/ 101) subtypes. Positive PTCH1 expression was found highest in nodular subtypes (46.5%). Conclusion: In this study, the correlation between low risk or high risk BCC subtypes and PTCH1 expression level was not statistically significant (p>0.05), but the frequency of positive PTCH1 expression was found to be higher in low risk subtypes than high risk BCC subtypes.

Erratum to "Basal Cell Carcinoma Pathology Requests and Reports Are Lacking Important Information".

[This corrects the article DOI: 10.1155/2019/4876309.].

A gain-of-function sodium channel ß2-subunit mutation in painful diabetic neuropathy.

Diabetes mellitus is a global challenge with many diverse health sequelae, of which diabetic peripheral neuropathy is one of the most common. A substantial number of patients with diabetic peripheral neuropathy develop chronic pain, but the genetic and epigenetic factors that predispose diabetic peripheral neuropathy patients to develop neuropathic pain are poorly understood. Recent targeted genetic studies have identified mutations in α-subunits of voltage-gated sodium channels (Navs) in patients with painful diabetic peripheral neuropathy. Mutations in proteins that regulate trafficking or functional properties of Navs could expand the spectrum of patients with Nav-related peripheral neuropathies. The auxiliary sodium channel ß-subunits (ß1-4) have been reported to increase current density, alter inactivation kinetics, and modulate subcellular localization of Nav. Mutations in ß-subunits have been associated with several diseases, including epilepsy, cancer, and diseases of the cardiac conducting system. However, mutations in ß-subunits have never been shown previously to contribute to neuropathic pain. We report here a patient with painful diabetic peripheral neuropathy and negative genetic screening for mutations in SCN9A, SCN10A, and SCN11A-genes encoding sodium channel α-subunit that have been previously linked to the development of neuropathic pain. Genetic analysis revealed an aspartic acid to asparagine mutation, D109N, in the ß2-subunit. Functional analysis using current-clamp revealed that the ß2-D109N rendered dorsal root ganglion neurons hyperexcitable, especially in response to repetitive stimulation. Underlying the hyperexcitability induced by the ß2-subunit mutation, as evidenced by voltage-clamp analysis, we found a depolarizing shift in the voltage dependence of Nav1.7 fast inactivation and reduced use-dependent inhibition of the Nav1.7 channel.

Basal Cell Carcinoma Pathology Requests and Reports Are Lacking Important Information.

INTRODUCTION: Basal cell carcinoma (BCC) is the most common cancer affecting humans. Luckily it has negligible risk for metastasis; however it can be locally destructive to surrounding tissue. The diagnosis of this tumor relies on clinical and dermoscopic features; however confirmation requires biopsy and histologic examination. Based on clinical and pathologic findings, BCC is classified as low or high risk subtype. The clinician requesting pathology examination for BCC should provide the pathologist with detailed information including patient details, relevant clinical and medical history, site and type of the biopsy, and whether this is a primary or recurrent lesion. The pathologist on the other hand should write an adequate report containing a minimum of core set of parameters including type of BCC, depth of invasion, presence of lymphovascular or perineural invasion, and the excision margins. OBJECTIVES: The objective of this study is to evaluate whether requests by clinicians and pathology reports of BCC are adequate. METHODS: This is a retrospective analysis done at the dermatology department, faculty of medicine at Jordan University of Science and Technology, Irbid, Jordan. Reports for the period from January 2003 to December 2017 were retrieved and analyzed for data completeness. RESULTS: Most clinical request forms of BCC provided by clinicians are inadequate and lack important relevant information especially in regard to lesion history, patient medical history, and whether BCC is a primary or a recurrent one. Pathology reports for BCC cases also have significant deficiency especially in describing the histologic subtype, depth of invasion, and presence of lymphovascular and perineural invasion. However, the tumor excision margins are adequately described in almost all reports. CONCLUSIONS: The study shows that clinicians do not provide adequate clinical information when submitting a request for histopathologic examination of BCC. Similarly, pathologists write incomplete reports that lack important pathologic features. Having pre-set forms (electronic proforma) can help overcome missing information.

Yield of peripheral sodium channels gene screening in pure small fibre neuropathy.

BACKGROUND: Neuropathic pain is common in peripheral neuropathy. Recent genetic studies have linked pathogenic voltage-gated sodium channel (VGSC) variants to human pain disorders. Our aims are to determine the frequency of SCN9A, SCN10A and SCN11A variants in patients with pure small fibre neuropathy (SFN), analyse their clinical features and provide a rationale for genetic screening. METHODS: Between September 2009 and January 2017, 1139 patients diagnosed with pure SFN at our reference centre were screened for SCN9A, SCN10A and SCN11A variants. Pathogenicity of variants was classified according to established guidelines of the Association for Clinical Genetic Science and frequencies were determined. Patients with SFN were grouped according to the VGSC variants detected, and clinical features were compared. RESULTS: Among 1139 patients with SFN, 132 (11.6%) patients harboured 73 different (potentially) pathogenic VGSC variants, of which 50 were novel and 22 were found in ≥ 1 patient. The frequency of (potentially) pathogenic variants was 5.1% (n=58/1139) for SCN9A, 3.7% (n=42/1139) for SCN10A and 2.9% (n=33/1139) for SCN11A. Only erythromelalgia-like symptoms and warmth-induced pain were significantly more common in patients harbouring VGSC variants. CONCLUSION: (Potentially) pathogenic VGSC variants are present in 11.6% of patients with pure SFN. Therefore, genetic screening of SCN9A, SCN10A and SCN11A should be considered in patients with pure SFN, independently of clinical features or underlying conditions.

Clinical and Demographic Features of Basal Cell Carcinoma in North Jordan.

Basal cell carcinoma (BCC) is the most common cancer affecting humans. It almost has no tendency for metastasis; however it can be destructive to surrounding tissue. Patients with darker skin colors have lower risk of developing skin cancers and the clinical characteristics may differ from populations with lighter skin colors. Methods. This is a retrospective clinical study (2003-2017). Data on age, gender, and location of tumor were collected and analyzed. Results. 335 cases were identified. Males tend to get BCC at a younger age than females. Face was the most common site in both males and females. Cheeks and nose were the most likely areas of the face to be involved. Scalp was the most common extrafacial site to be involved in males; however in females scalp was much less likely to be involved. Conclusion. BCC is less common in populations with darker skin. Males were more affected and at an earlier age compared to females. Facial skin followed by scalp was the most common site affected. Skin phototype, cultural and religious dress type, and different sun exposure behavior may explain many of the clinical and demographic findings related to BCC in patients with darker skin tones.

Mutations in CYB561 Causing a Novel Orthostatic Hypotension Syndrome.

RATIONALE: Orthostatic hypotension is a common clinical problem, but the underlying mechanisms have not been fully delineated. OBJECTIVE: We describe 2 families, with 4 patients in total, experiencing severe life-threatening orthostatic hypotension because of a novel cause. METHODS AND RESULTS: As in dopamine ß-hydroxylase deficiency, concentrations of norepinephrine and epinephrine in the patients were low. Plasma dopamine ß-hydroxylase activity, however, was normal, and the DBH gene had no mutations. Molecular genetic analysis was performed to determine the underlying genetic cause. Homozygosity mapping and exome and Sanger sequencing revealed pathogenic homozygous mutations in the gene encoding cytochrome b561 (CYB561); a missense variant c.262G>A, p.Gly88Arg in exon 3 in the Dutch family and a nonsense mutation (c.131G>A, p.Trp44*) in exon 2 in the American family. Expression of CYB561 was investigated using RNA from different human adult and fetal tissues, transcription of RNA into cDNA, and real-time quantitative polymerase chain reaction. The CYB561 gene was found to be expressed in many human tissues, in particular the brain. The CYB561 protein defect leads to a shortage of ascorbate inside the catecholamine secretory vesicles leading to a functional dopamine ß-hydroxylase deficiency. The concentration of the catecholamines and downstream metabolites was measured in brain and adrenal tissue of 6 CYB561 knockout mice (reporter-tagged deletion allele [post-Cre], genetic background C57BL/6NTac). The concentration of norepinephrine and normetanephrine was decreased in whole-brain homogenates of the CYB561(-/-) mice compared with wild-type mice (P<0.01), and the concentration of normetanephrine and metanephrine was decreased in adrenal glands (P<0.01), recapitulating the clinical phenotype. The patients responded favorably to treatment with l-dihydroxyphenylserine, which can be converted directly to norepinephrine. CONCLUSIONS: This study is the first to implicate cytochrome b561 in disease by showing that pathogenic mutations in CYB561 cause an as yet unknown disease in neurotransmitter metabolism causing orthostatic hypotension.