38 research outputs found
Bilinen Metabolik Hastalıklar ve Sendromlar ile İlişkilendirilemeyen Konjenital/Gelişimsel Kataraktlarda Yeni Nesil Dizileme ile Moleküler Etiyolojinin Araştırılması
No full textProje No: THD-2017-11983The aim of the study was to identify the molecular etiology in patients with congenital/developmental cataract which can not be attributed to known metabolic diseases or syndromes by next generation sequencing. A total of four patients (three girls and one boy) who had isolated bilateral cataract were enrolled in the study after detailed genetic and metabolic evaluation. Two patients had nuclear, one patient had total and one patient had combined lamellar and sutural cataract. All patients underwent bilateral lensectomy and anterior vitrectomy. One family had consanguinity. DNA (Deoxyribonucleic Acid) was extracted from peripheral blood of probands and selected affected individuals in the family. Whole exome sequencing (WES) was performed by IonProton® technology. The results were confirmed by Sanger sequencing. Heterozygous c.215+1G>A mutation in CRYBA1 was detected in one patient, heterozygous c.432C>G (p.Tyr144Ter) mutation in CRYGC was detected in one patient, heterozygous c.70A>C (p.Pro24Thr) mutation in CRYGD was detected in one patient and heterozygous c.466G>A (p.Gly156Arg) mutation in CRYBB3 was detected in one patient. All these mutations were also detected in selected affected individuals of the families and were located on the crystalline genes which have been previously reported to be associated with congenital cataract. The study highlights that crystalline genes should be considered in the first place when performing studies regarding the genetic etiology of the congenital cataract in our country and the implementation of WES as a useful technology in identifying the genetic basis of complex diseases such as congenital cataract. In addition, the present study has a unique property and is the first report of whole exome sequencing data in regard with congenital cataract in our country.Bu çalışmada amaç bilinen bir metabolik hastalık ve sendrom ile ilişkilendirilemeyen konjenital/gelişimsel kataraktı olan hastalarda yeni nesil dizileme ile moleküler etiyolojiyi tanımlamaktı. Çalışmaya ayrıntılı genetik ve metabolik değerlendirme sonrasında izole bilateral kataraktı olan üç kız bir erkek toplam dört hasta dahil edildi. İki hastada nükleer, bir hastada total, bir hastada ise kombine lamellar ve sütüral katarakt mevcuttu. Tüm hastalara bilateral lensektomi ve ön vitrektomi uygulandı. Bir ailede akraba evliliği mevcuttu. Hastaların ve ailedeki seçilmiş etkilenmiş bireylerin periferik kanından DNA (Deoksiribonükleik Asit) izole edildi. Tüm ekzom sekanslama (WES, Whole Exome Sequencing)) IonProton® teknolojisi ile yapıldı. Sonuçlar Sanger sekanslama ile konfirme edildi. Bir hastada CRYBA1 geninde heterozigot c.215+1G>A, bir hastada CRYGC geninde heterozigot c.432C>G (p.Tyr144Ter), bir hastada CRYGD geninde heterozigot c.70C>A (p.Pro24Thr) bir hastada ise CRYBB3 geninde heterozigot c.466G>A (p.Gly156Arg) mutasyonu saptandı. Tüm bu mutasyonlar ailenin seçilmiş etkilenmiş bireylerinde de gösterildi ve daha önce konjenital katarakt ile ilişkili olduğu bildirilmiş kristalin genleri üzerindeydi. Bu çalışma, ülkemizde konjenital kataraktın genetik etiyolojisine yönelik yapılan çalışmalarda kristalin genlerinin öncelikle düşünülmesi gerektiğini ve WES’in konjenital katarakt gibi kompleks hastalıklarda genetik temeli tanımlamakta yararlı bir teknoloji olarak kullanımını vurgulamaktadır. Ayrıca, bu çalışma benzersiz bir özelliğe sahiptir ve ülkemizde konjenital kataraktın tüm ekzom sekanslama bilgisine dair ilk bildiridir
Al-Gazali skeletal dysplasia constitutes the lethal end of ADAMTSL2-related disorders
No full textPublished May 2023Lethal short-limb skeletal dysplasia Al-Gazali type (OMIM %601356) is an ultra-rare disorder previously reported in only three unrelated individuals. The genetic etiology for Al-Gazali skeletal dysplasia has up until now been unknown. Through international collaborative efforts involving seven clinical centers worldwide, a cohort of nine patients with clinical and radiographic features consistent with short-limb skeletal dysplasia Al-Gazali type was collected. The affected individuals presented with moderate intrauterine growth restriction, relative macrocephaly, hypertrichosis, large anterior fontanelle, short neck, short and stiff limbs with small hands and feet, severe brachydactyly, and generalized bone sclerosis with mild platyspondyly. Biallelic disease-causing variants in ADAMTSL2 were detected using massively parallel sequencing (MPS) and Sanger sequencing techniques. Six individuals were compound heterozygous and one individual was homozygous for pathogenic variants in ADAMTSL2. In one of the families pathogenic variants were detected in parental samples only. Overall, this study sheds light on the genetic cause of Al-Gazali skeletal dysplasia and identifies it as a semi-lethal part of the spectrum of ADAMTSL2-related disorders. Furthermore, we highlight the importance of meticulous analysis of the pseudogene region of ADAMTSL2 where disease-causing variants might be located.Dominyka Batkovskyte, Fiona McKenzie, Fulya Taylan, Pelin Ozlem Simsek-Kiper, Sarah M Nikkel, Hirofumi Ohashi, Roger E Stevenson, Thuong Ha, Denise P Cavalcanti, Hiroyuki Miyahara, Steven A Skinner, Miguel A Aguirre, Zühal Akçören, Gulen Eda Utine, Tillie Chiu, Kenji Shimizu, Anna Hammarsjö, Koray Boduroglu, Hannah W Moore, Raymond J Louie, Peer Arts, Allie N Merrihew, Milena Babic, Matilda R Jackson, Nikos Papadogiannakis, Anna Lindstrand, Ann Nordgren, Christopher P Barnett, Hamish S Scott, Andrei S Chagin, Gen Nishimura, and Giedre Grigelionien
A Turkish BCS1L mutation causes GRACILE-like disorder
No full textA full-term growth-restricted female newborn (1790 g), presented with lactic acidosis (12.5 mmol/L) after birth. She had renal tubulopathy, cholestasis and elevated serum ferritin concentration (2819 ng/ml). Two similarly affected sisters had died before 3 months of age. Mitochondrial disorder was suspected since the disease resembled the Finnish GRACILE syndrome, caused by a homozygous mutation (c.232A>G) in BCS1L. Thus, we sequenced the BCS1L gene, encoding the assembly factor for respiratory chain complex III. The patient had a homozygous mutation (c.296C>T; p.P99L), for which both parents were heterozygous. In four previously published patients of Turkish origin, the same homozygous mutation resulted in complex III deficiency, tubulopathy, encephalopathy, and liver failure. The p.P99L mutation seems to be specific to Turkish population and leads to GRACILE-like or Leigh-like condition. Assembly defects in complex III should be investigated in the affected tissues, since fibroblasts may not exhibit the deficiency
Arterial tortuosity and aneurysm in a case of Loeys-Dietz syndrome type IB with a mutation p.R537P in the TGFBR2 gene
No full textWe report a 13-year-old girl with Loeys-Dietz syndrome (LDS) caused by a known transforming growth factor beta receptor II (TGFBR2) gene mutation, who developed aortic root dilatation and saccular aneurysm of the internal carotid artery. LDS is a rare, autosomal dominant aortic aneurysm syndrome with multisystem involvement. The disease is typically characterized by the triad of arterial tortuosity and aneurysms, hypertelorism, and bifid uvula/cleft palate. The characteristic LDS symptoms observed in the reported case included craniofacial dysmorphism (hypertelorism, cleft palate, blue sclerae, malar hypoplasia, retrognathia), skeletal deformities (scoliosis, talipes equinovarus, pectus deformity, arachnodactyly), congenital heart defects (patent ductus arteriosus, PDA), and arterial tortuosity and aneurysms. Molecular genetic testing revealed a heterozygous mutation (c.1610 G>C, p.R528C) in the serine-threonine kinase domain of the TGFBR2 gene. Magnetic resonance (MR) angiography showed aortic dilatation, tortuosity of bilateral supraaortic arteries, and saccular aneurysm on the right cervical internal carotid artery. LDS resembles Marfan-related disorders (Marfan, Shprintzen-Goldberg and vascular Ehlers-Danlos syndrome), but arterial tortuosity and aneurysms are characteristic for LDS, so a timely diagnosis of LDS is important for early diagnosis and intervention of aneurysms to prevent vascular events. Here, we describe a LDS patient who presented with arterial tortuosity and saccular aneurysm
Pseudo-trisomy 13 in a fetus: further support for autosomal recessive inheritance
No full textPseudo-trisomy 13 is defined in chromosomally normal patients with holoprosencephaly and associating features suggestive of trisomy 13. An autosomal recessive pattern of inheritance for this situation is most likely, but a gene for this condition has not yet been mapped. A fetus is presented with phenotypic features reminiscent of trisomy 13 but a normal karyotype, 46, XY. The pregnancy was terminated due to severe fetal malformations. In autopsy, the fetus had semilobar holoprosencephaly, hydrocephaly and dysmorphic features such as hypotelorism, cleft lip, a flat nose with a single nostril, low-set ears, postaxial polydactyly in all extremities, left unilateral pes equinovarus and pulmonary segmentation defect on the right. The parents were 2nd cousins once removed. Holoprosencephaly and polydactyly with or without other findings in chromosomally normal patients should raise the suspicion of pseudo-trisomy 13 syndrome, particularly when parental consanguinity is present
Noonan Sendromlu Bir Olguda Oktreotid ve Orta Zincirli Yağ Asitleri Kullanılarak Şilotoraksın Başarılı Tedavisi
No full textNoonan syndrome (NS), is an autosomal dominant disorder commonly seen in childhood and is characterized by short stature, congenital heart defects and facial abnormalities (especially in adults) along with thoracic deformity. Lymphatic dysplasia can be seen with this syndrome causing chylothorax by development of fistulas between thoracic duct and pleural space or it can directly occur by malformation of thoracic lymphatic vessels. Hence, chylothorax can also be seen. Herein, we present a case with this syndrome and chylothorax secondary to possible lymphatic dysplasia. We achieved a great success with ocreotide and medium chain trigliserides in the management of chylothorax and hence suggest this therapy to other clinicians.WoSScopu
Bi-allelic Mutations in KLHL7 Cause a Crisponi/CISS1-like Phenotype Associated with Early-Onset Retinitis Pigmentosa
No full textCrisponi syndrome (CS)/cold-induced sweating syndrome type 1 (CISS1) is a very rare autosomal-recessive disorder characterized by a complex phenotype with high neonatal lethality, associated with the following main clinical features: hyperthermia and feeding difficulties in the neonatal period, scoliosis, and paradoxical sweating induced by cold since early childhood. CS/CISS1 can be caused by mutations in cytokine receptor-like factor 1 (CRLF1). However, the physiopathological role of CRLF1 is still poorly understood. A subset of CS/CISS1 cases remain yet genetically unexplained after CRLF1 sequencing. In five of them, exome sequencing and targeted Sanger sequencing identified four homozygous disease-causing mutations in kelch-like family member 7 (KLHL7), affecting the Kelch domains of the protein. KLHL7 encodes a BTB-Kelch-related protein involved in the ubiquitination of target proteins for proteasome-mediated degradation. Mono-allelic substitutions in other domains of KLHL7 have been reported in three families affected by a late-onset form of autosomal-dominant retinitis pigmentosa. Retinitis pigmentosa was also present in two surviving children reported here carrying bi-allelic KLHL7 mutations. KLHL7 mutations are thus associated with a more severe phenotype in recessive than in dominant cases. Although these data further support the pathogenic role of KLHL7 mutations in a CS/CISS1-like phenotype, they do not explain all their clinical manifestations and highlight the high phenotypic heterogeneity associated with mutations in KLHL7
Derivative chromosome 1 and <it>GLUT1 </it>deficiency syndrome in a sibling pair
No full textAbstract Background Genomic imbalances constitute a major cause of congenital and developmental abnormalities. GLUT1 deficiency syndrome is caused by various de novo mutations in the facilitated human glucose transporter 1 gene (1p34.2) and patients with this syndrome have been diagnosed with hypoglycorrhachia, mental and developmental delay, microcephaly and seizures. Furthermore, 1q terminal deletions have been submitted in the recent reports and the absence of corpus callosum has been related to the deletion between C1orf100 and C1orf121 in 1q44. Results This study reports on a sibling pair with developmental delay, mental retardation, microcephaly, hypotonia, epilepsy, facial dysmorphism, ataxia and impaired speech. Chromosome analysis revealed a derivative chromosome 1 in both patients. FISH and MCB analysis showed two interstitial deletions at 1p34.2 and 1q44. SNP array and array-CGH analysis also determined the sizes of deletions detailed. The deleted region on 1p34.2 encompasses 33 genes, among which is GLUT1 gene (SLC2A1). However, the deleted region on 1q44 includes 59 genes and distal-proximal breakpoints were located in the ZNF672 gene and SMYD3 gene, respectively. Conclusion Haploinsufficiency of GLUT1 leads to GLUT1 deficiency syndrome, consistent with the phenotype in patients of this study. Conversely, in the deleted region on 1q44, none of the genes are related to findings in these patients. Additionally, the results confirm previous reports on that corpus callosal development may depend on the critical gene(s) lying in 1q44 proximal to the SMYD3 gene.</p
Clinical and Molecular Spectrum of Four Patients Diagnosed with Mowat-Wilson Syndrome
No full textMowat-Wilson syndrome (MWS) is a rare autosomal dominant syndrome characterized by distinctive facial features, congenital heart defects, Hirschsprung disease, genitourinary anomalies, various structural brain anomalies, and intellectual disability. Pathogenic mutations that result in haploinsufficiency in the ZEB2 gene cause MWS. in this study, we aimed to evaluate the clinical features and molecular analysis results of 4 MWS patients. All patients were examined by an expert clinical geneticist. Dysmorphological abnormalities were recorded. Data including demographic, clinical, and laboratory findings were obtained from hospital records. ZEB2 gene analysis was performed using a Sanger sequencing method. All patients had typical facial features of MWS such as widely spaced eyes, broad eyebrows with a medial flare, low-hanging columella, prominent or pointed chin, open-mouth expression, and uplifted earlobes. Four different heterozygous mutations were identified; 2 mutations were frameshift (c.246_247delGGinsC, c.980_980delG), 1 was nonsense (c.2083C>T), and 1 was splice site (c.808-2A>G). Two of them (c.246_247delGGinsC, c.980_980delG) have not been previously reported in the literature. By defining 2 novel mutations, this study contributes to the molecular spectrum of MWS, while also providing a further insight for genetic counseling. It also demonstrates the importance of dysmorphological examination in clinical diagnosis
Exome sequencing unravels unexpected differential diagnoses in individuals with the tentative diagnosis of Coffin-Siris and Nicolaides-Baraitser syndromes
No full textCoffin-Siris syndrome (CSS) and Nicolaides-Baraitser syndrome (NCBRS) are rare intellectual disability/congenital malformation syndromes that represent distinct entities but show considerable clinical overlap. They are caused by mutations in genes encoding members of the BRG1- and BRM-associated factor (BAF) complex. However, there are a number of patients with the clinical diagnosis of CSS or NCBRS in whom the causative mutation has not been identified. In this study, we performed trio-based whole-exome sequencing (WES) in ten previously described but unsolved individuals with the tentative diagnosis of CSS or NCBRS and found causative mutations in nine out of ten individuals. Interestingly, our WES analysis disclosed overlapping differential diagnoses including Wiedemann-Steiner, Kabuki, and Adams-Oliver syndromes. In addition, most likely causative de novo mutations were identified in GRIN2A and SHANK3. Moreover, trio-based WES detected SMARCA2 and SMARCA4 deletions, which had not been annotated in a previous Haloplex target enrichment and next-generation sequencing of known CSS/NCBRS genes emphasizing the advantages of WES as a diagnostic tool. In summary, we discuss the phenotypic and diagnostic challenges in clinical genetics, establish important differential diagnoses, and emphasize the cardinal features and the broad clinical spectrum of BAF complex disorders and other disorders caused by mutations in epigenetic landscapers
