BackgroundOsteogenesis imperfecta (OI) is a heterogeneous bone disorder characterized by recurrent fractures. Although most cases of OI have heterozygous mutations in COL1A1 or COL1A2 and show autosomal dominant inheritance, during the last years there has been an explosion in the number of genes responsible for both recessive and dominant forms of this condition. Herein, we have analyzed a cohort of patients with OI, all offspring of unaffected parents, to determine the spectrum of variants accounting for these cases. Twenty patients had nonrelated parents and were sporadic, and 21 were born to consanguineous relationships.MethodsMutation analysis was performed using a next‐generation sequencing gene panel, homozygosity mapping, and whole exome sequencing (WES).ResultsPatients offspring of nonconsanguineous parents were mostly identified with COL1A1 or COL1A2 heterozygous changes, although there were also a few cases with IFITM5 and WNT1 heterozygous mutations. Only one sporadic patient was a compound heterozygote for two recessive mutations. Patients offspring of consanguineous parents showed homozygous changes in a variety of genes including CRTAP,FKBP10,LEPRE1,PLOD2,PPIB,SERPINF1,TMEM38B, and WNT1. In addition, two patients born to consanguineous parents were found to have de novo COL1A1 heterozygous mutations demonstrating that causative variants in the collagen I structural genes cannot be overlooked in affected children from consanguineous couples. Further to this, WES analysis in probands lacking mutations in OI genes revealed deleterious variants in SCN9A,NTRK1, and SLC2A2, which are associated with congenital indifference to pain (CIP) and Fanconi–Bickel syndrome (FBS).ConclusionThis work provides useful information for clinical and genetic diagnosis of OI patients with no positive family history of this disease. Our data also indicate that CIP and FBS are conditions to be considered in the differential diagnosis of OI and suggest a positive role of SCN9A and NTRK1 in bone development.

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Congenital central hypothyroidism (CCH) is a very rare disease. Alterations in pituitary development genes as well as mutations of immunoglobulin superfamily member 1 and transducin β-like protein 1 can result in CCH and multiple pituitary hormone deficiencies. However, mutations of the thyrotropin-releasing hormone receptor or thyroid-stimulating hormone-beta (TSHB) gene are responsible for isolated CCH. In this paper, we present the cases of two siblings with a novel mutation of TSHB. Direct sequencing of the coding regions and exon/intron boundaries of the TSHB gene revealed two homozygous nucleotides changes. One of them was c.40A>G (rs10776792) which is a very common variation that is also seen in healthy individuals, the other was c.94G>A at codon 32 of exon 2 which resulted in a change from glutamic acid to lysine (p.E32K). Both patients were homozygous and the parents were heterozygous.

Intracytoplasmic sperm injection (ICSI) is a widespread and powerful method enabling men with low sperm quantity and quality to become fathers. However, compared with naturally conceived children, there are increased risks of problems, such as congenital malformations, chromosomal abnormalities, infertility, epigenetic diseases, and delayed neuropsychological development in the offspring. We present the case of 6-year-old male patient born following ICSI with clinical and radiological features of Goldenhar syndrome as well as a history of surgery for unilateral cryptorchidism. His karyotyping showed a chromosomal constitution of 47, XXY. Clinicians should be aware of the risks of an increasing number of patients born following ICSI to maximize children's health and welfare.

The aim of this study is to evaluate the diagnosis characteristics, clinic findings, phenotypical and genotypical features of children with GM2 gangliosidoses. Materials and Methods: The file records of 14 patients diagnosed with GM2 gangliosidoses in our clinic were retrospectively reviewed. The GM2 gangliosidoses diagnosis was confirmed by determining the levels of serum total hexosaminidase and β-hexosaminidase activity with genetic analysis. Results: We identified a total of seven different mutations, three of which were novel (one in the HEXA gene and two in the HEXB gene) in 14 patients. We found a high frequency of c.1100_1111del (p.Gly367_Tyr370del) mutation in HEXA affected patients. The mean age at diagnosis was 13.46.3 months and 14.24.2 months for patients with Tay-Sachs disease (TSD) and Sandhoff disease (SD) respectively. Neuroregression was present in 92.9% of our patients. Of the 14 patients, 11 had epilepsy, 10 had developmental delay, 6 had hyperacusis, 6 had cherry-red spots and 6 had macrocephaly, but none of the patients had organomegaly. Conclusion: GM2 gangliosidoses disease should be considered for children with developmental regression and/or delay. For early diagnosis, enzyme analysis and gene detection should be performed in children with suspected GM2 gangliosidoses in the presence of clinical findings.Amaç: Bu çalışmanın amacı, GM2 gangliosidozlu çocukların tanı özelliklerini, klinik bulgularını, fenotipik ve genotipik özelliklerini değerlendirmektir. Gereç ve Yöntem: Kliniğimizde GM2 gangliosidoz tanısı alan 14 hastanın dosya kayıtları retrospektif olarak incelendi. GM2 gangliosidoz tanısı; serum total heksosaminidaz ile β-heksosaminidaz aktivitesi düzeyleri ve genetik analiz ile doğrulandı. Bulgular: On dört hastada üçü novel (biri HEXA geninde ve ikisi HEXB geninde) olmak üzere toplam yedi farklı mutasyon saptandı. HEXA mutasyonu olan hastalarda c.1100_1111del (p.Gly367_Tyr370del) mutasyonu yüksek sıklıkta bulundu. Tay-Sachs (TSD) ve Sandhoff (SD) tanılı hastaların ortalama tanı yaşı sırasıyla 13,4±6,3 ay ve 14,2±4,2 aydı. Hastaların %92.9'unda nöroregresyon mevcuttu. On dört hastanın 11'inde epilepsi, 10'unda gelişim geriliği, 6'sında hiperakuzi, 6'sında cherry-red spot ve 6'sında makrosefali saptanırken, hiçbir hastada organomegali görülmedi. Sonuç: Gelişim geriliği ve/veya gecikmesi olan çocuklarda GM2 gangliosidoz hastalığı akla gelmelidir. GM2 gangliosidoz şüphesi olan çocuklarda klinik bulgular varlığında erken tanı için enzim analizi ve gen tespiti yapılmalıdır.