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Cardiofaciocutaneous (CFC) syndrome is one of the developmental disorders caused by a dysregulation of the Ras/mitogen-activated protein kinase (MAPK) pathway. RASopathies share overlapping clinical features, making the diagnosis challenging, especially in the newborn period. The majority of CFC syndrome cases arise by a mutation in the <i>BRAF</i>, <i>MAP2K1</i>,<i> MAP2K2</i>, or (rarely) <i>KRAS</i> genes. Germline <i>KRAS</i> mutations are identified in a minority of CFC and Noonan syndrome cases. Here, we describe a patient with a <i>KRAS</i> mutation presenting with a CFC syndrome phenotype. The female patient was referred for genetic testing because of congenital exophthalmos. Her facial appearance is distinctive with a coarse face, exophthalmos, ptosis, downslanting palpebral fissures, hypertelorism, deep philtrum, downturned corners of the mouth, and a short neck. She suffered from feeding difficulties, poor weight gain, and developmental delay. The sequencing of the genes involved in the MAPK pathway (<i>PTPN11</i>,<i> SOS1</i>,<i> RAF1</i>,<i> KRAS</i>,<i> NRAS</i>,<i> MAP2K1</i>,<i> SHOC2</i>,<i> CBL</i>,<i> and SPRED1</i>) identified a heterozygous de novo NM_004985.4:c.173C>T (p.Thr58Ile) in the <i>KRAS</i> gene. Germline <i>KRAS </i>mutations have been identified in approximately 2% of the reported NS cases and less than 5% of the reported CFC syndrome cases. Because CFC and Noonan syndrome share clinical overlapping features, the phenotype caused by <i>KRAS</i> mutations is often difficult to assign to one of the 2 entities. The mutation that we detected in our patient was previously reported in a patient with an Noonan syndrome phenotype. However, our patient predominantly exhibits CFC clinical features. In our case, coarse facial appearance and severe developmental delay help discriminate CFC from Noonan syndrome. Thus, patient follow-up, especially for delayed motor milestones suspected from RASopathies, is important for the discrimination of overlapping conditions as in the abovementioned syndromes.

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<b><i>Introduction:</i></b> Germline pathogenic variations of the genes encoding the components of the Ras-MAPK pathway are found to be responsible for RASopathies, a clinically and genetically heterogeneous group of diseases. In this study, we aimed to present the results of patients genetically investigated for RASopathy-related mutations in our Genetic Diagnosis Center. <b><i>Methods:</i></b> The results of 51 unrelated probands with RASopathy and 4 affected relatives (31 male, 24 female; mean age: 9.327 ± 8.214) were included in this study. Mutation screening was performed on DNA samples from peripheral blood of the patients either by Sanger sequencing of <i>PTPN11</i> hotspot regions (10/51 probands), or by a targeted amplicon next-generation sequencing panel (41/51 probands) covering the exonic regions of <i>BRAF</i>, <i>CBL</i>, <i>HRAS</i>, <i>KRAS</i>, <i>LZTR1</i>, <i>MAP2K1</i>, <i>MAP2K2</i>, <i>NF1</i>, <i>NRAS</i>, <i>PTPN11</i>, <i>RAF1</i>, <i>RASA2</i>, <i>RIT1</i>, <i>SHOC2</i>, <i>SOS1</i>, <i>SOS2</i>, <i>SPRED1</i>, and <i>KAT6B</i> genes. <b><i>Results:</i></b> Pathogenic/likely pathogenic variations found in 22 out of 51 probands (43.13%) and their 4 affected family members were located in <i>PTPN11</i>, <i>BRAF</i>, <i>KRAS</i>, <i>NF1</i>, <i>RAF1</i>, <i>SOS1</i>, and <i>SHOC2</i> genes. The c.148A&#x3e;C (p.Thr50Pro) variation in the <i>KRAS</i> gene was a novel variant detected in a sibling in our patient cohort. We found supportive evidence for the pathogenicity of the <i>NF1</i> gene c.5606G&#x3e;T (p.Gly1869Val) variation which we defined in an affected boy who inherited the mutation from his affected father. <b><i>Conclusion:</i></b> Although <i>PTPN11</i> is the most frequently mutated gene in our patient cohort, as in most previous reports, different mutation distribution among the other genes studied motivates the use of a next-generation sequencing gene panel including the possible responsible genes.

We aimed to determine the etiology of hypertransaminasemia in children, demonstrate the differences according to the age and evaluate course of transaminases. Method: We retrospectively analyzed the medical records of children who presented with elevated transaminase levels for at least 2 months, aged between 3 months and 18 years, for demographic features, laboratory, radiologic and histopathological findings. Results: Among total 292 children, 194 (66.4%) were male and 98 (33.6%) were female. The mean age was 6.5±5.4 years. The 45.9% of the children had no complaints at presentation. Majority of the patients had mildly elevated transaminases (81.6%). The most common etiology was nonalcoholic fatty liver disease (NAFLD) (25.7%). The NAFLD was more prevelant in patients older than 5 years-old (p<0.001). The second cause was infectious diseases (97.8% were viral infections) and more prevelant in patients younger than 2 years-old (p=0.043). In 34.1 % of the children, no overt cause of hypertransaminasemia was identified. The patients with unidentified etiology were significantly younger, but had higher mean aspartate aminotransferase (AST) levels than the patients in whom the etiology was identified (p= <0.0001, p=0.008 respectively). The normalization of transaminases was seen in 40.4% of the patients at mean 5.4±4.4 months. The shortest normalization time was observed in drug related liver injury (DILI) among all other etiologies (p=0.015). Conclusions:The most common cause of hypertransaminasemia in childhood were NAFLD and viral infections, which varies by age. A stepwise approachment to hypertransaminasemia leads to early diagnosis.

Amaç: Çölyak hastalığı (ÇH), genetik yatkınlığı olan bireylerde, glutene kalıcı duyarlılık sonucu gelişen, otoimmün, sistemik hastalıktır. Bu çalışmanın amacı, ÇH’nin klinik, laboratuar özellikleri ve HLA doku tiplerinin geriye dönük değerlendirilmesidir.Ayrıca lieratür taramasıyla HLA doku tipleri açısından Türkiye’de bölgelere göre farklılık ve benzerliklerin incelenmesidir. Yöntem: Çalışmaya, Temmuz 2017- Ekim 2018 tarihleri arasında ÇH tanısıyla izlenen ve genetik çalışması uygulanan 104 çocuk alındı. Google Scholarda Türkiye’de ÇH ve HLA genotiplendirme ile yapılan çalışmalar tarandı (n=11 çalışma) ve bölgelere ayrıldı. Bulgular: Çalışmaya alınan 104 hastanın 67’si kız (%64,4) ve ortalama tanı yaşı 7,9±2,38 yıl(10ay-17,2yıl) idi. Hastalarımızın HLA grupları %59,6 DQ2, %26,9 DQ8 ve %13,4 DQ2+DQ8 saptandı. Literatürdeki çalışmalar bölgeler göre değerlendirildiğinde bizim de içinde bulunduğumuz Karadeniz bölgesinde HLADQ2 %63,7 ve HLADQ8 %21,1 sıklıkla görülürken, bölgemize benzer oranlarda genotip sıklığı Akdeniz ve Doğu Anadolu bölgelerinde görülmektedir. İç Anadolu HLADQ2 %87,4 ve Marmara bölgesinde %83,6 ile daha yüksek frekansta görülmektedir. Çalışmamızda, DQA1*05 %65,4 ve DQB1*02 %12,5 oranında bulundu. Türkiye’deki diğer çalışmalarda (Marmara, Karadeniz, İç, Doğu ve Güneydoğu Anadolu Bölgeleri) görülme sıklığı DQA1*05%69,8 ve DQB1*02 %27,7 idi. Çalışmamızda HLA DQB1*02 homozigot olan hastalarda (%12,5) boy kısalığı, ishal, demir eksikliği anemisi, Marsh3 evre ve akrabalarında ÇH daha yüksekti. Sonuç: Çölyak hastalığında HLA-DQ analizi bölgesel sıklığın belirlenmesi genetik analiz maliyetini azaltmak ve bölgesel dağılıma göre özellikle semptomsuz tarama hastalarında genotiplenme yapılması erken tanı kolaylığı sağlayabilir.

Background: Myotonia congenita is the most common form of nondystrophic myotonia and is caused by Mendelian inherited mutations in the CLCN1 gene encoding the voltage-gated chloride channel of skeletal muscle. Objective: The study aimed to describe the clinical and genetic spectrum of Myotonia congenita in a large pediatric cohort. Methods: Demographic, genetic, and clinical data of the patients aged under 18 years at time of first clinical attendance from 11 centers in different geographical regions of Türkiye were retrospectively investigated. Results: Fifty-four patients (mean age:15.2 years (±5.5), 76% males, with 85% Becker, 15% Thomsen form) from 40 families were included. Consanguineous marriage rate was 67%. 70,5% of patients had a family member with Myotonia congenita. The mean age of disease onset was 5.7 (±4.9) years. Overall 23 different mutations (2/23 were novel) were detected in 52 patients, and large exon deletions were identified in two siblings. Thomsen and Becker forms were observed concomitantly in one family. Carbamazepine (46.3%), mexiletine (27.8%), phenytoin (9.3%) were preferred for treatment. Conclusions: The clinical and genetic heterogeneity, as well as the limited response to current treatment options, constitutes an ongoing challenge. In our cohort, recessive Myotonia congenita was more frequent and novel mutations will contribute to the literature.

Trizomi 8 Mozaisizm Sendromu (T8MS) (Warkany Sendromu) insanlarda bazı hücrelerde ekstra bir 8. kromozom varlığıyla tanımlanan nadir bir kromozomal bozukluktur. T8MS, bir dizi gelişimsel anormallik ile ilişkili klinik olarak oldukça değişken bir sendromdur (1,5). Bu çalışmada çoklu konjenital anomalileri ve dismorfik yüz görünümü olan bir T8MS olgusu sunulmuştur. 3.5 aylık erkek çocuk atipik yüz görünümü nedeni ile genetik bölümüne refere edilmişti. Fizik muayenesinde mikrosefali, hipertelorizm, basık burun kökü, derin yerleşimli gözler, strabismus, displastik kulaklar, yarık damak, derin el ve ayak çizgileri, kamptodaktili ve hipotonisite mevcuttu. İşitme kaybı, sol gözde periferal noktasal katarakt, bilateral ileri evre vezikoüreteral reflü, korpus kallozum disgenezisi gibi ek anomalileri mevcuttu. Hastanın kromozom analizinde trizomi 8 mozaisizmi tespit edildi (47,XY,+8[11]/46,XY[39]). Floresan in situ hibridizasyon analizi ile de mozaiklik doğrulandı. T8MS klinik olarak oldukça heterojen olup dismorfizm, ürogenital anomaliler, korpus kallozum agenezisi, kamptodaktili gibi bulgular sıklıkla eşlik eder. Derin el ve ayak çizgileri T8MS için oldukça karakteristiktir. Bizim hastamızda da daha önce literatürde bildirilmiş T8MS ile ilişkili konjenital anomalilere sahipti. Genetik anormalliklerin klinik fenotip ile korelasyonu, sendromik tanının konması için her zaman önemlidir. Sonuç olarak çok sayıda konjenital anomalilerin eşlik ettiği dismorfik hastalarda her zaman için kromozomal hastalıklar olabileceği ayırıcı tanıda düşünülmelidir ve öncelikle sitogenetik incelemeler yapılmalıdır.