Homozygous microdeletion in the 11p13 region in the patient with isolated form of aniridia: New challenges in the genetic diagnostics of aniridia.

Aniridia is usually an autosomal dominant, rare disorder characterized by a variable degree of hypoplasia or the absence of iris tissue, with additional ocular abnormalities. Pathogenic variants in the PAX6 gene are associated with aniridia in most patients. However, in up to 30% of individuals, disease results from 11p13 chromosomal rearrangements. Here we present a patient with a clinical diagnosis of partial aniridia born to consanguineous Polish parents. The parents were asymptomatic and ophthalmologically normal. We performed PAX6 sequencing, array comparative genomic hybridization, quantitative real-time PCR, and whole genome sequencing. aCGH revealed a homozygous deletion of the DCDC1 gene fragment in the patient. The same, but heterozygous deletion, was detected in each of the patient's asymptomatic parents and brother. In the presented family, the signs and symptoms of aniridia are observed only in the homozygous proband. Whole genome sequencing analysis was performed to determine other possible causes of the disease and did not detect any additional or alternative potentially pathogenic variant. We report a novel homozygous deletion located in the 11p13 region, which does not include the PAX6 gene or any known PAX6 enhancers. To our best knowledge, this is the first reported case of a patient presented with isolated aniridia carrying a homozygous microdeletion downstream of the PAX6 gene.

NKX2-5 Variant in Two Siblings with Thyroid Hemiagenesis.

Thyroid hemiagenesis (THA) is an inborn absence of one thyroid lobe of largely unknown etiopathogenesis. The aim of the study was to reveal genetic factors responsible for thyroid maldevelopment in two siblings with THA. None of the family members presented with congenital heart defect. The samples were subjected to whole-exome sequencing (WES) (Illumina, TruSeq Exome Enrichment Kit, San Diego, CA 92121, USA). An ultra-rare variant c.839C>T (p.Pro280Leu) in NKX2-5 gene (NM_004387.4) was identified in both affected children and an unaffected father. In the mother, the variant was not present. This variant is reported in population databases with 0.0000655 MAF (GnomAD v3, dbSNP rs761596254). The affected amino acid position is moderately conserved (positive scores in PhyloP: 1.364 and phastCons: 0.398). Functional prediction algorithms showed deleterious impact (dbNSFP v4.1, FATHMM, SIFT) or benign (CADD, PolyPhen-2, Mutation Assessor). According to ACMG criteria, variant is classified as having uncertain clinical significance. For the first time, NKX2-5 gene variants were found in two siblings with THA, providing evidence for its potential contribution to the pathogenesis of this type of thyroid dysgenesis. The presence of the variant in an unaffected parent, carrier of p.Pro280Leu variant, suggests potential contribution of yet unidentified additional factors determining the final penetrance and expression.

"Slipped capital femoral epiphysis in a 25-year-old hypogonadic man with a large cranial chondroma: causality or coincidence? ".

BACKGROUND: Slipped capital femoral epiphysis (SCFE) is a hip disorder frequently occurring in adolescence. In adults it is rare and so far very few cases have been documented. CASE PRESENTATION: This report presents a 25-year-old patient diagnosed with an anterior fossa giant chondroma, hypogonadotropic hypogonadism, and SCFE. The patient underwent surgical and hormonal therapy. His symptoms revealed, and he became a father. CONCLUSIONS: Every patient diagnosed with SCFE in adulthood should undergo endocrinological assessment based on physical examination and laboratory tests.

Head and Neck Paragangliomas-A Genetic Overview.

Pheochromocytomas (PCC) and paragangliomas (PGL) are rare neuroendocrine tumors. Head and neck paragangliomas (HNPGL) can be categorized into carotid body tumors, which are the most common, as well as jugular, tympanic, and vagal paraganglioma. A review of the current literature was conducted to consolidate knowledge concerning PGL mutations, familial occurrence, and the practical application of this information. Available scientific databases were searched using the keywords head and neck paraganglioma and genetics, and 274 articles in PubMed and 1183 in ScienceDirect were found. From these articles, those concerning genetic changes in HNPGLs were selected. The aim of this review is to describe the known genetic changes and their practical applications. We found that the etiology of the tumors in question is based on genetic changes in the form of either germinal or somatic mutations. 40% of PCC and PGL have a predisposing germline mutation (including VHL, SDHB, SDHD, RET, NF1, THEM127, MAX, SDHC, SDHA, SDHAF2, HIF2A, HRAS, KIF1B, PHD2, and FH). Approximately 25-30% of cases are due to somatic mutations, such as RET, VHL, NF1, MAX, and HIF2A. The tumors were divided into three main clusters by the Cancer Genome Atlas (TCGA); namely, the pseudohypoxia group, the Wnt signaling group, and the kinase signaling group. The review also discusses genetic syndromes, epigenetic changes, and new testing technologies such as next-generation sequencing (NGS).

Copy Number Variants Contributing to Combined Pituitary Hormone Deficiency.

Combined pituitary hormone deficiency represents a disorder with complex etiology. For many patients, causes of the disease remain unexplained, despite usage of advanced genetic testing. Although major and common transcription factors were identified two decades ago, we still struggle with identification of rare inborn factors contributing to pituitary function. In this report, we follow up genomic screening of CPHD patient cohort that were previously tested for changes in a coding sequences of genes with the use of the whole exome. We aimed to find contribution of rare copy number variations (CNVs). As a result, we identified genomic imbalances in 7 regions among 12 CPHD patients. Five out of seven regions showed copy gains whereas two presented losses of genomic fragment. Three regions with detected gains encompassed known CPHD genes namely LHX4, HESX1, and OTX2. Among new CPHD loci, the most interesting seem to be the region covering SIX3 gene, that is abundantly expressed in developing brain, and together with HESX1 contributes to pituitary organogenesis as it was evidenced before in functional studies. In conclusion, with the use of broadened genomic approach we identified copy number imbalances for 12 CPHD patients. Although further functional studies are required in order to estimate its true impact on expression pattern during pituitary organogenesis and CPHD etiology.

Differences in Mutational Profile between Follicular Thyroid Carcinoma and Follicular Thyroid Adenoma Identified Using Next Generation Sequencing.

We aimed to identify differences in mutational status between follicular thyroid adenoma (FTA) and follicular thyroid cancer (FTC). The study included 35 patients with FTA and 35 with FTC. DNA was extracted from formalin-fixed paraffin-embedded (FFPE) samples from thyroidectomy. Next-generation sequencing (NGS) was performed with the 50-gene Ion AmpliSeq Cancer Hotspot Panel v2. Potentially pathogenic mutations were found in 14 (40%) FTA and 24 (69%) FTC patients (OR (95%CI) = 3.27 (1.22-8.75)). The number of mutations was higher in patients with FTC than FTA (p-value = 0.03). SMAD4 and STK11 mutations were present only in patients with FTA, while defects in FBXW7, JAK3, KIT, NRAS, PIK3CA, SMARCB1, and TP53 were detected exclusively in FTC patients. TP53 mutations increased the risk of FTC; OR (95%CI) = 29.24 (1.64-522.00); p-value = 0.001. FLT3-positivity was higher in FTC than in the FTA group (51.4% vs. 28.6%; p-value = 0.051). The presence of FLT3 and TP53 with no RET mutations increased FTC detectability by 17.1%, whereas the absence of FLT3 and TP53 with a presence of RET mutations increased FTA detectability by 5.7%. TP53 and FLT3 are candidate markers for detecting malignancy in follicular lesions. The best model to predict FTA and FTC may consist of FLT3, TP53, and RET mutations considered together.

Determinants of Visfatin/NAMPT Serum Concentration and its Leukocyte Expression in Hyperthyroidism.

We aimed to analyze the potential influence of thyroid autoimmunity on visfatin/NAMPT serum concentration and its leukocyte expression in hyperthyroid patients. This is a single-center, cross-sectional study with consecutive enrollment. All patients with newly diagnosed overt hyperthyroidism in a course of Graves' disease or toxic nodular goiter were included in the study. They underwent physical examination, laboratory investigation, body composition analysis, and thyroid ultrasound. NAMPT mRNA leukocyte expressions were measured using RT-qPCR. Of the 173 patients, 95 were enrolled in further analysis [67 patients with Graves' disease (GD) and 28 with toxic nodular goiter (TNG)]. Control group consisted of 43 healthy volunteers adjusted for age, sex, and BMI. Higher NAMPT/visfatin serum concentration was found in patients with GD comparing with patients with TNG (p=0.03855). We found significant NAMPT leukocyte overexpression in GD patients (n=32) as compared to TNG patients (n=18) and euthyroid controls (n=24) (p=0.005965). Simple linear regression analysis revealed that NAMPT/visfatin serum concentration was significantly associated with NAMPT leukocyte expression, thyroid autoimmunity, age, HOMA-IR, and fat mass percentage (FM%). NAMPT leukocyte expression was related to thyroid autoimmunity, age, and TRAb levels. The stepwise multiple regression analysis revealed FM% and HOMA-IR as independent predictors of visfatin/NAMPT serum levels. In a separate stepwise multiple regression analysis, we confirmed the association between NAMPT leukocyte expression and TRAb levels. We found that fat mass percentage together with HOMA-IR are the most significant predictors of visfatin/NAMPT serum elevation in hyperthyroid patients.

Increased STAG2 dosage defines a novel cohesinopathy with intellectual disability and behavioral problems.

Next generation genomic technologies have made a significant contribution to the understanding of the genetic architecture of human neurodevelopmental disorders. Copy number variants (CNVs) play an important role in the genetics of intellectual disability (ID). For many CNVs, and copy number gains in particular, the responsible dosage-sensitive gene(s) have been hard to identify. We have collected 18 different interstitial microduplications and 1 microtriplication of Xq25. There were 15 affected individuals from 6 different families and 13 singleton cases, 28 affected males in total. The critical overlapping region involved the STAG2 gene, which codes for a subunit of the cohesin complex that regulates cohesion of sister chromatids and gene transcription. We demonstrate that STAG2 is the dosage-sensitive gene within these CNVs, as gains of STAG2 mRNA and protein dysregulate disease-relevant neuronal gene networks in cells derived from affected individuals. We also show that STAG2 gains result in increased expression of OPHN1, a known X-chromosome ID gene. Overall, we define a novel cohesinopathy due to copy number gain of Xq25 and STAG2 in particular.

The c.470 T > C CHEK2 missense variant increases the risk of differentiated thyroid carcinoma in the Great Poland population.

BACKGROUND: Differentiated thyroid carcinoma (DTC) originates from thyroid follicular epithelial cells and belongs to a group of slowly progressing tumors with a relatively good prognosis. However, recurrences and metastases are a serious problem in advanced stages. Furthermore, progression from a well differentiated thyroid carcinoma to an aggressive anaplastic one is possible. The majority of differentiated thyroid carcinomas are sporadic but a few alleles increasing the cancer risk are known. One of them is the c.470 T > C (p.I157T, rs17879961) missense substitution in the CHEK2 gene. AIM OF THE STUDY: The aim of this study was to investigate whether this specific CHEK2 alteration, c.470 T > C, predisposes the Great Poland (Wielkopolska) population to thyroid cancer. METHODS: 602 differentiated thyroid carcinoma patients and 829 controls randomly selected from population were genotyped for the presence of the c.470C allele using pyrosequencing. Hardy-Weinberg Equilibrium (HWE) was tested for both groups by chi-square distribution and Fisher's exact test. The odds ratios (ORs), 95% confidence intervals (CIs), and p-values were calculated using the R software. RESULTS: The results of genotyping showed the presence of the c.470C allele in 51 patients with a frequency of 4.49%, while in a controls in 42 patients with a frequency of 2.53%. We demonstrated that in the Great Poland population the c.470C CHEK2 variant increases the risk of developing differentiated thyroid cancer almost twice (OR = 1.81, p = 0.004). The risk of papillary thyroid carcinoma in female patients homozygous for the c.470C allele was shown to increase almost 13-fold (OR = 12.81, p = 0.019). CONCLUSIONS: Identification of c.470C CHEK2 gene variant ought to be taken into account by healthcare policymakers. Future well-designed and larger population studies are of great value in confirming these findings. Moreover, a combination of genetic factors together with environmental exposures should also be considered.

The influence of radioiodine therapy on ocular changes and their relation to urine cotinine level in patients with Graves' Ophthalmopathy.

OBJECTIVES: Radioiodine therapy (RIT) is frequently used as the definitive treatment in patients with Graves' hyperthyroidism when remission is not achieved with anti-thyroid drugs (ATDs). In this observational study, we intended to examine whether the use of high doses of radioiodine (RAI) [22 mCi (814 MBq)] with prophylaxis of oral glucocorticoids (oGCS) does not exacerbate Graves ophthalmopathy (GO) in smokers and non-smokers, especially regards to the urine level cotinine and ocular changes before and after RIT. PATIENTS AND METHODS: The studied group consisted of 26 smokers, aged 28-61 years and 25 non-smoker patients, aged 21-54 years, respectively. The patients were enrolled to RAI after one-year of ineffective ATDs treatment. Criterion for inclusion in the study were patients with mild GO with hyperthyroidism at diagnosis based on the severity (NOSPECTS) and activity (CAS) scale. All the patients were subjected to RIT with oGCS prophylaxis and evaluated prospectively during a one-year follow-up. The ophthalmological examination was performed at various stages of RIT: initial pre-radioiodine administration, at the time of treatment 6, and 12 months after RAI. The present study is unique, because the urine cotinine measurement was employed to detect nicotine exposure, also in regard to smoking intensity. RESULTS: In smokers, the values of serum TPO-Abs were statistically significant in the second and six month (p<0.05) and in the second and after one year (p<0.005). The TSHR-Abs concentration was significantly higher in smokers (p<0.05), rising from 22.9±1.2 IU/L before therapy to 29.6±5.3 IU/L - 2 months, 32.6±8.6 IU/L - 6 months, and slightly decreased 28.9±10.6 IU/L - 12 months. These observed changes were statistically different between groups at baseline (p<0.05) and after one-year of follow-up (p<0.005). Mean urine cotinine were considerably higher in smokers comparing to non smokers in each point of observation [903.4±770.0 and 5.2±1.7 ng/mL at baseline (p<0.001), 412.8±277.3 and 3.0±0.6 ng/mL after 2 months (p<0.001), 452.0±245 and 6.6±3.6 after 6 months (p<0.001), 379.4±236.8 and 1.0±1.2 after one year (p<0.001)]. The CAS values in the smoking group before RIT increased statistically from 2.8±0.2 points at baseline to 4.3±0.3 after 6 months, and 4.0±0.5 (12 months), while in the non-smoking patients it was 1.4±0.2, 2.8±0.3 and 2.2±0.2, respectively. The level of urine cotinine correlated positively with CAS and TSHR-Ab in the smoking group (r=0.41; p<0.05) at baseline and during follow-up (2 months: r=0.46; p<0.001, 6 months: r=0.47, p<0.005; 12 months: r=0.46; p<0.005). In the NOSPECS classification, the symptoms changed from mild to moderate, mostly in smoking patients. CONCLUSIONS: 1) ablative RIT dose with prophylactic oral prednisone is a safe treatment in both smokers and non-smokers with mild GO; 2) The post hoc analysis showed that urinary level of cotinine can be very helpful in the assessment of exacerbation of ophthalmological clinical symptoms before and after RIT particularly in smokers.

[131I]I-MIBG-negative metastases of a recurrent sporadic paraganglioma in a female with achondroplasia.

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Follicular Thyroid Adenoma and Follicular Thyroid Carcinoma-A Common or Distinct Background? Loss of Heterozygosity in Comprehensive Microarray Study.

Pre- and postsurgical differentiation between follicular thyroid adenoma (FTA) and follicular thyroid cancer (FTC) represents a significant diagnostic challenge. Furthermore, it remains unclear whether they share a common or distinct background and what the mechanisms underlying follicular thyroid lesions malignancy are. The study aimed to compare FTA and FTC by the comprehensive microarray and to identify recurrent regions of loss of heterozygosity (LOH). We analyzed formalin-fixed paraffin-embedded (FFPE) samples acquired from 32 Caucasian patients diagnosed with FTA (16) and FTC (16). We used the OncoScan™ microarray assay (Affymetrix, USA), using highly multiplexed molecular inversion probes for single nucleotide polymorphism (SNP). The total number of LOH was higher in FTC compared with FTA (18 vs. 15). The most common LOH present in 21 cases, in both FTA (10 cases) and FTC (11 cases), was 16p12.1, which encompasses many cancer-related genes, such as TP53, and was followed by 3p21.31. The only LOH present exclusively in FTA patients (56% vs. 0%) was 11p11.2-p11.12. The alteration which tended to be detected more often in FTC (6 vs. 1 in FTA) was 12q24.11-q24.13 overlapping FOXN4, MYL2, PTPN11 genes. FTA and FTC may share a common genetic background, even though differentiating rearrangements may also be detected.

OFD1 is mutated in X-linked Joubert syndrome and interacts with LCA5-encoded lebercilin.

We ascertained a multi-generation Malaysian family with Joubert syndrome (JS). The presence of asymptomatic obligate carrier females suggested an X-linked recessive inheritance pattern. Affected males presented with mental retardation accompanied by postaxial polydactyly and retinitis pigmentosa. Brain MRIs showed the presence of a "molar tooth sign," which classifies this syndrome as classic JS with retinal involvement. Linkage analysis showed linkage to Xpter-Xp22.2 and a maximum LOD score of 2.06 for marker DXS8022. Mutation analysis revealed a frameshift mutation, p.K948NfsX8, in exon 21 of OFD1. In an isolated male with JS, a second frameshift mutation, p.E923KfsX3, in the same exon was identified. OFD1 has previously been associated with oral-facial-digital type 1 (OFD1) syndrome, a male-lethal X-linked dominant condition, and with X-linked recessive Simpson-Golabi-Behmel syndrome type 2 (SGBS2). In a yeast two-hybrid screen of a retinal cDNA library, we identified OFD1 as an interacting partner of the LCA5-encoded ciliary protein lebercilin. We show that X-linked recessive mutations in OFD1 reduce, but do not eliminate, the interaction with lebercilin, whereas X-linked dominant OFD1 mutations completely abolish binding to lebercilin. In addition, recessive mutations in OFD1 did not affect the pericentriolar localization of the recombinant protein in hTERT-RPE1 cells, whereas this localization was lost for dominant mutations. These findings offer a molecular explanation for the phenotypic spectrum observed for OFD1 mutations; this spectrum now includes OFD1 syndrome, SGBS2, and JS.

Progressing Vulvar Melanoma Caused by Instability in cKIT Juxtamembrane Domain: A Case Report and Review of Literature.

In order to identify the molecular pathways governing melanoma and track its progression, the next-generation sequencing (NGS) approach and targeted sequencing of cancer genes were employed. The primary tumor, as well as metastatic tissue, of an 84-year-old patient diagnosed with vulvar melanoma (VM), were investigated. The primary tumor specimen showed multiple somatic mutations in TP53 gene, suggesting its major contribution to melanoma origin. The metastatic sample showed additional alterations, including other melanoma-related genes. Clinical relevancy is postulated to juxtamembrane region instability of KIT gene (c-KIT). We did not identify BRAF or NRAS alterations, which are typical for the most common melanoma pathway-MAPK cascade. However, it should be noted that this is the first report evidencing PDGFRA in melanoma, although its role in triggering VM needs to be further elucidated.

Compound heterozygous GLI3 variants in siblings with thyroid hemiagenesis.

PURPOSE: Thyroid hemiagenesis (THA) is an inborn absence of one thyroid lobe of largely unknown etiopathogenesis, affecting 0.05-0.5% population. The aim of the study was an identification of genetic factors responsible for thyroid maldevelopment in two siblings with THA. METHODS: We evaluated a three-generation THA family with two sisters presenting the disorder. Proband (Patient II:3) was diagnosed at the age of 45 due to neck asymmetry. Left lobe agenesis and nontoxic multinodular goiter were depicted. Proband's sister (Patient II:6) was euthyroid, showed up at the age of 39 due to neck discomfort and left-sided THA was demonstrated. Affected individuals were subjected to whole-exome sequencing (WES) (Illumina, TruSeq Exome Kit) and all identified variants were evaluated for pathogenicity. Sanger sequencing was used to confirm WES data and check segregation among first-degree relatives. RESULTS: In both siblings, a compound heterozygous mutations NM_000168.6: c.[2179G>A];[4039C>A] (NP_000159.3: p.[Gly727Arg];[Gln1347Lys]) were identified in the GLI3 gene, affecting exon 14 and 15, respectively. According to the American College of Medical Genetics, variants are classified as of uncertain significance, and were found to be very rare (GnomAD MAF 0.007131 and 0.00003187). The segregation mapping and analysis of relatives indicated causativeness of compound heterozygosity. CONCLUSIONS: We demonstrated for the first time a unique association of THA phenotype and the presence of compound heterozygous mutations p.[Gly727Arg];[Gln1347Lys] of GLI3 gene in two siblings.

Defects in GnRH Neuron Migration/Development and Hypothalamic-Pituitary Signaling Impact Clinical Variability of Kallmann Syndrome.

Kallmann syndrome (KS) is a combination of isolated hypogonadotropic hypogonadism (IHH) with olfactory dysfunction, representing a heterogeneous disorder with a broad phenotypic spectrum. The genetic background of KS has not yet been fully established. This study was conducted on 46 Polish KS subjects (41 males, 5 females; average age: 29 years old). The studied KS patients were screened for defects in a 38-gene panel with next-generation sequencing (NGS) technology. The analysis revealed 27 pathogenic and likely pathogenic (P/LP) variants, and 21 variants of uncertain significance (VUS). The P/LP variants were detected in 20 patients (43.5%). The prevalence of oligogenic P/LP defects in selected genes among KS patients was 26% (12/46), whereas the co-occurrence of other variants was detected in 43% (20 probands). The examined KS patients showed substantial genotypic and phenotypic variability. A marked difference in non-reproductive phenotypes, involving defects in genes responsible for GnRH neuron development/migration and genes contributing to pituitary development and signaling, was observed. A comprehensive gene panel for IHH testing enabled the detection of clinically relevant variants in the majority of KS patients, which makes targeted NGS an effective molecular tool. The significance of oligogenicity and the high incidence of alterations in selected genes should be further elucidated.

CDON gene contributes to pituitary stalk interruption syndrome associated with unilateral facial and abducens nerve palsy.

The relationship between congenital defects of the brain and facial anomalies was proven. The Hedgehog signaling pathway plays a fundamental role in normal craniofacial development in humans. Mutations in the sonic hedgehog (SHH) signaling gene CDON have been recently reported in patients with holoprosencephaly and with pituitary stalk interruption syndrome (PSIS). This study's aim was an elucidation of an 18-year-old patient presenting PSIS, multiple pituitary hormone deficiency, and congenital unilateral facial and abducens nerve palsy. Additionally, bilateral sensorineural hearing loss, dominating at the right site, was diagnosed. From the second year of life, growth deceleration was observed, and from the age of eight, anterior pituitary hormone deficiencies were gradually confirmed and substituted. At the MRI, characteristic triad for PSIS (anterior pituitary hypoplasia, interrupted pituitary stalk and ectopic posterior lobe) was diagnosed. We performed a comprehensive genomic screening, including microarrays for structural rearrangements and whole-exome sequencing for a monogenic defect. A novel heterozygous missense variant in the CDON gene (c.1814G > T; p.Gly605Val) was identified. The variant was inherited from the mother, who, besides short stature, did not show any disease symptoms. The variant was absent in control databases and 100 healthy subjects originating from the same population. We report a novel variant in the CDON gene associated with PSIS and congenital cranial nerve palsy. The variant revealed autosomal dominant inheritance with incomplete penetrance in concordance with previous studies reporting CDON defects.

High incidence of FLT3 mutations in follicular thyroid cancer: potential therapeutic target in patients with advanced disease stage.

BACKGROUND: Conventional treatments for follicular thyroid cancer (FTC) can be ineffective, leading to poor prognosis. The aim of this study was to identify mutations associated with FTC that would serve as novel molecular markers of the disease and its outcome and could potentially identify new therapeutic targets. METHODS: FLT3 mutations were first detected in a 29-year-old White female diagnosed with metastasized, treatment-refractory FTC. Analyses of FLT3 mutational status through next-generation sequencing of formalin-fixed, paraffin-embedded FTC specimens were subsequently performed in 35 randomly selected patients diagnosed with FTC. RESULTS: FLT3 mutations were found in 69% of patients. FLT3 mutation-positive patients were significantly older than those that were FLT3 mutation-negative [median age at diagnosis 54 (36-82) versus 45 (27-58) (p = 0.023)]. Patients over 60 years were 23 times more likely to be FLT3 mutation-positive (p = 0.006). However, the number of FLT3 mutations did not correlate with age (r-Pearson: -0.244, p-value: 0.25). A total of 26 mutations were identified in the FLT3 gene with 2-16 FLT3 mutations in each FLT3 mutation-positive patient (mean: 5.6 mutations/patient). Tyrosine kinase domain (TKD) mutations in the FLT3 gene were detected in 58% of FLT3 mutation-positive patients. All FLT3 mutation-positive patients with a disease stage of pT2N1 or worse harbored at least one mutation in the TKD of FLT3. CONCLUSIONS: There is a wide spectrum and high frequency of FLT3 mutations in FTC. The precise role of FLT3 mutations in the genesis of FTC, as well as its potential role as a therapeutic target, requires further investigation.

SEMA3A and IGSF10 Are Novel Contributors to Combined Pituitary Hormone Deficiency (CPHD).

Background: The mutation frequencies of pituitary transcription factors genes in patients with combined pituitary hormone deficiencies (CPHD) vary substantially between populations. However, apart from PROP1 the mutation rate of other genes is low and for almost half of the patients with CPHD the routine sequencing of known genes is unsuccessful in the identification of genetic causes. Methods: A cohort of 66 sporadic and nine familial CPHD cases (80 patients in total) were subjected to initial testing of the genes PROP1, POU1F1, LHX3, LHX4, and HESX1 using a targeted gene panel and MLPA. In patients who tested negative, a whole exome sequencing approach was employed. Results: In nine of the familial cases and 32 of the sporadic patients mutations in the PROP1 gene were found (the common pathogenic variants included c.301_302delAG and c.150delA). Mutations were also found in genes so far not related directly to CPHD. A unique homozygous and clinically relevant variant was identified in the SEMA3A gene, which may contribute to neural development and his phenotypic spectrum including short stature and isolated hypogonadotropic hypogonadism (IHH). Another pathogenic variant p.A1672T was found in the IGSF10 gene reported to be responsible for delayed puberty and neuronal migration during embryogenesis. Several suspected novel but predicted benign variants were also identified for the CHD7, WDR11 and FGF17 genes. Conclusion: Although PROP1 defects account for a majority of CPHD patients, identification of rare, less frequent variants constitutes a big challenge. Multiple genetic factors responsible for CPHD are still awaiting discovery and therefore the usage of efficient genomic tools (i.e., whole exome sequencing) will further broaden our knowledge regarding pituitary development and function.

Genetic heterogeneity of indeterminate thyroid nodules assessed preoperatively with next-generation sequencing reflects the diversity of the final histopathologic diagnosis.

INTRODUCTION: Inconclusive cytologic results of thyroid fine­needle aspiration biopsy (FNAB) include atypia or follicular lesion of undetermined significance (FLUS) and follicular neoplasm or suspicious for follicular neoplasm (SFN). OBJECTIVES: We aimed to assess the genetic background of indeterminate thyroid nodules and to identify new genetic pathways potentially involved in the development of follicular thyroid cancer. PATIENTS AND METHODS: Genomic DNA was isolated from FNAB samples from 25 white patients (2 men; 23 women) diagnosed preoperatively with FLUS (n = 16) and SFN (n = 9). Next­generation sequencing (NGS) was performed. The results were compared with clinical data, including final postsurgical diagnoses. RESULTS: The malignancy rate was 28%. KDR, RET, and TP53 gene mutations were most frequent in FLUS and SFN samples finally diagnosed as cancers, whereas alterations in RET, TP53, FLT3, APC, and PDGFRA predominated in benign tumors. KDR tended to be more common in malignant samples (75% vs 20%, P = 0.1). A total number of mutated genes was higher in patients with benign tumors (17 vs 11, P = 0.02), but there was no difference between groups in the mean number of mutations per patient (4.9 [range, 1-9]). CONCLUSIONS: We showed that the heterogeneity in the genetic background of indeterminate thyroid nodules corresponds to their histopathologic diversity. The role of KDR as a possible malignancy marker needs to be confirmed. Glass slides with FNAB samples may constitute a reliable source of genetic material for NGS studies, providing a better insight into the molecular profile of thyroid nodules.