Copy number variation analysis in 189 Romanian patients with global developmental delay/intellectual disability.

BACKGROUND: Developmental delay and intellectual disability represent a common pathology in general population, involving about 3% of the pediatric age population, the genetic etiology being often involved. The aim of this study was to determine the clinically relevant copy number variants in patients diagnosed with global developmental delay/intellectual disability in our population, using the chromosomal microarray analysis. METHODS: We analyzed 189 patients diagnosed with global developmental delay/intellectual disability, presented in Clinical Emergency Hospital for Children, Cluj-Napoca. The patients were completely clinically investigated, including dysmorphic and internal malformations evaluation, psychiatric, neuropsychological and metabolic evaluation, standard karyotyping. Genomic analysis was done using chromosomal microarray analysis. RESULTS: Pathogenic findings (including uniparental disomy) and variants of unknown significance were detected in 53 of 189 patients (28.04%). Pathogenic copy number variants and uniparental disomy were observed in 35 of 189 patients (18.51%). Two patients presented uniparental disomy for chromosome 15, one with clinical phenotype of Prader-Willi syndrome and the other with clinical phenotype with Angelman syndrome. Within the category of pathogenic findings, the recurrent copy number variants were seen in 21 of 35 patients (60%). CONCLUSIONS: The increased percentage of pathogenic structural variants observed in patients with global developmental delay/intellectual disability analyzed by chromosomal microarray technique supports its use in patients with a non-specific phenotype such as these neurodevelopmental disorders. The high percentage of recurrent pathogenic variants between these findings is a finding that support their initial evaluation when a genetic testing algorithm could be a useful option.

Evaluation of Circulating Chitotriosidase Activity in Children with Obesity.

Childhood obesity progresses to metabolic disturbances via low-grade inflammation. Identifying novel molecules that reflect the activity of the immune responses is critical in understanding its underlying pathogenesis. Our exploratory study aimed to evaluate the change of chitotriosidase (CHIT1) plasma activity according to Body Mass Index (BMI)-for-age z score in pediatric patients. The study evaluated 68 children consisting of 47.1% girls with a mean age of 12.47 ± 3.71 years and 52.9% boys with a mean age of 11.93 ± 3.18 years. The effect of the most frequent CHIT1 gene variants, the 24 base pair duplication (dup24) and G102S polymorphism, upon the association between circulating CHIT1 activity and the obesity level, was also investigated. A significantly higher logCHIT1 plasma activity was found in children with extreme obesity than in children with overweight (p = 0.048 for the uncorrected CHIT1 and 0.026 for the corrected CHIT1). The BMI-for-age z score significantly (p = 0.031) predicts increased CHIT1 activity in children with overweight, obesity, and extreme obesity after controlling for the two gene variants, age, gender, and time since weight gain. Dup24 and G102S polymorphism were significant independent predictors (p-values < 0.002) for the change of CHIT1 plasma activity. Circulating CHIT1 might be an accurate indicator of inflammation in children with obesity. Its role and the effect of the dup24 and G102S variants on the CHIT1 activity should be validated in a larger cohort.

Non-Syndromic Hearing Loss in a Romanian Population: Carrier Status and Frequent Variants in the GJB2 Gene.

The genetic causes of autosomal recessive nonsyndromic hearing loss (ARNSHL) are heterogeneous and highly ethnic-specific. We describe GJB2 (connexin 26) variants and carrier frequencies as part of our study and summarize previously reported ones for the Romanian population. In total, 284 unrelated children with bilateral congenital NSHL were enrolled between 2009 and 2018 in northwestern Romania. A tiered diagnostic approach was used: all subjects were tested for c.35delG, c.71G>A and deletions in GJB6 (connexin 30) using PCR-based methods. Furthermore, 124 cases undiagnosed at this stage were analyzed by multiplex-ligation-dependent probe amplifications (MLPA), probe mix P163, and sequencing of GJB2 exon 2. Targeted allele-specific PCR/restriction fragment length polymorphism (RFLP) established definite ethio-pathogenical diagnosis for 72/284 (25.35%) of the cohort. Out of the 124 further analyzed, in 12 cases (9.67%), we found compound heterozygous point mutations in GJB2. We identified one case of deletion of exon 1 of the WFS1 (wolframin) gene. Carrier status evaluation used Illumina Infinium Global Screening Array (GSA) genotyping: the HINT cohort-416 individuals in northwest Romania, and the FUSE cohort-472 individuals in southwest Romania. GSA variants yielded a cumulated risk allele presence of 0.0284. A tiered diagnostic approach may be efficient in diagnosing ARNSHL. The summarized contributions to Romanian descriptive epidemiology of ARNSHL shows that pathogenic variants in the GJB2 gene are frequent among NSHL cases and have high carrier rates, especially for c.35delG and c.71G>A. These findings may serve in health strategy development.

Molecular and Cytogenetic Analysis of Romanian Patients with Differences in Sex Development.

Differences in sex development (DSD) are often correlated with a genetic etiology. This study aimed to assess the etiology of DSD patients following a protocol of genetic testing. MATERIALS AND METHODS: This study prospectively investigated a total of 267 patients with DSD who presented to Clinical Emergency Hospital for Children Cluj-Napoca between January 2012 and December 2019. Each patient was clinically, biochemically, and morphologically evaluated. As a first intervention, the genetic test included karyotype + SRY testing. A high value of 17-hydroxyprogesterone was found in 39 patients, in whom strip assay analysis of the CYP21A2 gene was subsequently performed. A total of 35 patients were evaluated by chromosomal microarray technique, and 22 patients were evaluated by the NGS of a gene panel. RESULTS: The karyotype analysis established the diagnosis in 15% of the patients, most of whom presented with sex chromosome abnormalities. Genetic testing of CYP21A2 established a confirmation of the diagnosis in 44% of patients tested. SNP array analysis was particularly useful in patients with syndromic DSD; 20% of patients tested presented with pathogenic CNVs or uniparental disomy. Gene panel sequencing established the diagnosis in 11 of the 22 tested patients (50%), and the androgen receptor gene was most often involved in these patients. The genes that presented as pathogenic or likely pathogenic variants or variants of uncertain significance were RSPO1, FGFR1, WT1, CHD7, AR, NIPBL, AMHR2, AR, EMX2, CYP17A1, NR0B1, GNRHR, GATA4, and ATM genes. CONCLUSION: An evaluation following a genetic testing protocol that included karyotype and SRY gene testing, CYP21A2 analysis, chromosomal analysis by microarray, and high-throughput sequencing were useful in establishing the diagnosis, with a spectrum of diagnostic yield depending on the technique (between 15 and 50%). Additionally, new genetic variants not previously described in DSD were observed.

Genetic testing in pediatric endocrine pathology.

In genetic endocrine diseases, genetic testing is necessary for a precise diagnosis, which will provide a better knowledge of the evolution and prognosis and also indicate the adequate therapy, targeting the precise etiopathogenesis of the disease. Genetic testing in endocrinology is often based on classical cytogenetic techniques, molecular cytogenetic analysis or molecular biology techniques. Genetic testing in disorders of sex development includes the karyotype and SRY gene analysis and depending on the presence of associated clinical signs and on the observations at paraclinical examination, these tests will be followed by chromosomal array techniques and NGS sequencing. In short stature, the decision to perform a genetic test is taken depending on clinical, paraclinical and imaging signs. In case of a short stature associated with a low weight/length for gestational age, genetic testing is proposed to evaluate a Russell-Silver syndrome or if the short stature is associated with other clinical signs (e.g. intellectual disability), chromosomal analysis by microarray is proposed. If the short stature is disproportionate, it is indicated to perform a next generation sequencing (NGS) of a panel of genes involved in skeletal dysplasia. If an endocrine cause for short stature is observed at the hormonal evaluation, it is indicated to test a panel of genes involved in these pathways. In genetic obesity, depending on clinical signs associated to obesity, it will be a more targeted genetic testing. If obesity is associated with intellectual disability or other nonspecific neurological changes, a chromosomal analysis by microarray will be indicated. If monogenic obesity is suspected, NGS testing will be indicated (as genes panel or whole exome or genome analysis). Genetic testing in endocrine diseases brings an etiological diagnosis, but a favorable cost-benefit ratio derives from an adequate indication of these tests, generally proposed in expert centers for rare endocrine diseases.

Diagnostic, treatment and outcome possibilities in achondroplasia.

INTRODUCTION: Achondroplasia is a common form of chondrodysplasia. It is transmitted by autosomal dominant trait. The disease is determined by mutations in receptor-3 gene of the fibroblast growth factor. The most frequent mutations are c.1138G>A and c.1183G>C; c.1138A. The diagnosis can usually be made on the basis of clinical characteristics and specific features on radiographs. It is not necessary to perform molecular testing in every child with a clinical diagnosis of achondroplasia.The aim of this study is to establish the diagnostic, treatment and outcome possibilities in patients with achondroplasia in our care. METHOD: The study group consisted of 27 patients with achondroplasia. The method consisted of: clinical and radiological examinations. The DNA analasys was performed by PCR-RFLP technique. RESULTS: 80 patients were diagnosed with bone dysplasia; 24 of them were diagnosed (on clinical and radiological basis) with achondroplasia. Out of this group, 16 patients were identified as heterozygotes for G1138A mutation in FGFR3 gene; 3 patients undergoing treatment with somatotropic hormone; the growth rate is improving from 0.1 cm/month to 0.5 cm/month. CONCLUSIONS: In achondroplasia diagnosis is based on clinical and radiological criteria. It is the first study that reports the prevelance of this mutation in Romania.

Early clinical signs in lysosomal diseases.

BACKGROUND AND AIM: The lysosomal storage diseases are a group of monogenic diseases with multisystemic impairment and chronic progression induced by the deficiency of lysosomal acid hydrolases involved in the breakdown of various macromolecules. The accumulation occurs in the macrophages of the reticule-endothelial system and causes enlargement and functional impairment. The mainly involved organs are the brain, liver, spleen, bones, joints, airways, lungs, and heart. The aim of this study was to evaluate early symptoms, signs and the delay in the diagnosis of different lysosomal diseases. METHODS: The medical documentation of 188 patients with lysosomal storage disorders, aged 1-70 years, were analyzed. All these patients were specifically diagnosed, by enzyme and molecular assay. RESULTS: The age of clinical signs onset varies in different type of lysosomal diseases, from the first months of life or early childhood in severe form, to adulthood in attenuated forms. The delay between the clinical signs onset and specific diagnosis ranged from 0.5 months to 57.91 years. CONCLUSIONS: The lysosomal storage diseases are rare diseases with childhood onset, but these early signs and symptoms are not recognized and are often taken into account when the vital organs damage becomes manifest.

Diagnostic Usefulness of MLPA Techniques for Recurrent Copy Number Variants Detection in Global Developmental Delay/Intellectual Disability.

BACKGROUND: Genetic testing has become a standardized practice in the diagnosis of patients with global developmental delay/intellectual disability (GDD/ID). The aim of this study is to observe the frequency of recurrent copy number variations (CNVs) in patients diagnosed with GDD/ID, using MLPA technique. METHODS: A total of 501 paediatric patients with GDD/ID were analysed using SALSA MLPA probemix P245 Microdeletion Syndromes-1A, and the technical steps were performed according to the MRC Holland MLPA general protocol. RESULTS: Twenty-five of 501 patients (5%) were diagnosed with a microdeletion/microduplication syndrome. Amongst them, 7 of 25 (30%) with clinical suggestion have a confirmed diagnosis, for the other cases the clinical features were not evocative for a specific syndrome. CONCLUSION: This study showed that in cases with a specific clinical diagnosis the MLPA technique could be a useful alternative, less expensive and more efficient to indicate as first intention of a targeted diagnostic test, as it is the case of Williams syndrome, Prader-Willi syndrome or DiGeorge syndrome.

46,XX DSD: Developmental, Clinical and Genetic Aspects.

Differences in sex development (DSD) in patients with 46,XX karyotype occur by foetal or postnatal exposure to an increased amount of androgens. These disorders are usually diagnosed at birth, in newborns with abnormal genitalia, or later, due to postnatal virilization, usually at puberty. Proper diagnosis and therapy are mostly based on the knowledge of normal development and molecular etiopathogenesis of the gonadal and adrenal structures. This review aims to describe the most relevant data that are correlated with the normal and abnormal development of adrenal and gonadal structures in direct correlation with their utility in clinical practice, mainly in patients with 46,XX karyotype. We described the prenatal development of structures together with the main molecules and pathways that are involved in sex development. The second part of the review described the physical, imaging, hormonal and genetic evaluation in a patient with a disorder of sex development, insisting more on patients with 46,XX karyotype. Further, 95% of the etiology in 46,XX patients with disorders of sex development is due to congenital adrenal hyperplasia, by enzyme deficiencies that are involved in the hormonal synthesis pathway. The other cases are explained by genetic abnormalities that are involved in the development of the genital system. The phenotypic variability is very important in 46,XX disorders of sex development and the knowledge of each sign, even the most discreet, which could reveal such disorders, mainly in the neonatal period, could influence the evolution, prognosis and life quality long term.

Skeletal Abnormalities and VDR1 Gene Polymorphisms in Mucopolysaccharidosis Patients.

INTRODUCTION: Articular and bone damage, which is so disabling in Mucopolysaccharidosis (MPS), requires attention as to the explanatory bias of the pathogenetic mechanisms identified to date. The vitamin D receptor (VDR) has been investigated in many studies in correlation with bone metabolism, osteoporosis, and the impaired bone mineral density associated with certain polymorphisms of the VDR gene. AIM: This study aims to observe whether there is an association between clinical features, phospho-calcium metabolism parameters and the VDR gene polymorphisms in patients with MPS. PATIENTS AND METHOD: We evaluated six patients with MPS type I, 20 patients with MPS type II, two patients with MPS types IIIA and IIIB and three patients with MPS type IVB. In these patients, phospho-calcium metabolism, markers of bone formation, bone radiographs and bone densitometry were evaluated, as were four polymorphisms of the VDR gene (ApaI, BsmI, FokI and TaqI). RESULTS: There was a deficiency in 25 hydroxy vitamin D in MPS type I patients at the final evaluation and in MPS type II patients, both at ERT initiation and at the last evaluation. The analysed polymorphisms were not associated with modified calcium-phosphor levels, but some differences were observed regarding the level of 25 OH vitamin D. Thus, in the case of AA polymorphism, all patients have a 25 OH vitamin D deficiency, and one patient with the AA genotype and three with Aa have a 25 OH vitamin D deficiency and secondary hyperparathyroidism due to this deficiency (four patients), all of them having the Bb phenotype. CONCLUSION: In MPS patients, vitamin D deficiency is observed, as it is in some patients with secondary hyperparathyroidism, which indicates vitamin D supplementation to protect bone metabolism. There are no obvious correlations between VDR polymorphism and bone metabolism in MPS patients.

Clinical and genetic characteristics in a group of 45 patients with Turner syndrome (monocentric study).

INTRODUCTION: Recent years have seen a shift in perspective on Turner syndrome, as it is no longer considered a significant disability due to therapeutic advances. The delay of diagnosis and the underdiagnosis are common in Turner syndrome, especially because of the great phenotypic variability and lack of firm diagnostic criteria. AIM: Our first aim was to assess the clinical and the cytogenetic characteristics and growth rate in growth hormone (GH)-treated patients as compared to those with spontaneous growth. The second aim was to analyze the Y chromosomal sequences. MATERIALS AND METHODS: We analyzed 45 patients diagnosed with Turner syndrome in Genetic Pathology Centre of Cluj Emergency Children's Hospital. We carried out a study of the clinical features, the correlations between the karyotype and the phenotype, and we also made a research of Y chromosome sequences. RESULTS: The average age at diagnosis was 8.9±5.4 years. A significant association was observed between the number of external phenotypical abnormalities and internal malformations (r=0.45), particularly the cardiovascular ones (r=0.44). Patients treated with GH showed improvement in growth rate, with final stature significantly better than in untreated patients; benefits following treatment were greater if diagnosis was made before the age of 5 years. Thirteen percent of patients experienced spontaneous and complete puberty, whereas 30% experienced incomplete puberty. Patients with the 45,X genotype had a greater stature deficit and a higher incidence of cardiac malformations, compared with patients with 45,X/46,XX mosaic karyotype. Y chromosome sequences were found in only one patient, who subsequently underwent gonadectomy. CONCLUSION: The importance of this study resides, to the best of our knowledge, in the fact that the largest group of patients in Romania was analyzed and assessed. To draw firm conclusions on the most valuable clinical indicators for Turner syndrome diagnosis in clinical practice, studies on large groups of patients should be conducted.

Clinical and Genetic Characteristics of Romanian Patients with Mucopolysaccharidosis Type II.

BACKGROUND: Mucopolysaccharidosis type II (MPS II, Hunter syndrome) is a rare X-linked disorder caused by deficiency of iduronate-2-sulfatase (I2S) enzyme, which leads to the accumulation of partially digested glycosaminoglycans (GAGs) in the lysosomes and induces multisystemic alteration (coarse facial features; skeletal dysplasia; hepatosplenomegaly; joint stiffness and contractures; heart, lung, vision, and hearing disability; profound neurological decline).The purpose of this study is to present the clinical and genetic characteristics of Romanian patients with Hunter syndrome and the genotype-phenotype correlation. MATERIAL AND METHODS: 15 unrelated patients, with MPS II ranging from mild (4 subjects) to severe phenotype (11 subjects) aged 2 to 20 years, were evaluated clinically, cognitive development, enzyme assay and molecular analysis. RESULTS: The molecular analysis of the 15 unrelated Romanian MPS II patients has identified 15 different mutations (2 major genetic defects (13%) and 13 minor genetic defects (87%)): microdeletions and point mutations (missense, nonsense), seven of them described for the first time-deletion encompassing 3 to exon 7; c823G>T, pD275Y; c.1600A>C (pN534H); c.102_10delAG (p.D5Cfs*11); c.448_471del (p.P150_P157del); c.421delA (p.I141Yfs*72); and c.419-1G>C. The major genetic defects were correlated with a severe course of disease. CONCLUSION: This is the first study on the clinical and molecular characterization of the MPS II Romanian patients. This study supports the evidence of the mutational heterogeneity of the I2S gene as well as the difficulty to correlate genotype and phenotype in the patients with MPS II.

Alterations in lipid and carbohydrate metabolism in patients with classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency.

BACKGROUND: Classic 21-hydroxylase deficiency (21HD) presents some traits of the metabolic syndrome. AIM: To characterize discrete alterations of lipid and carbohydrate metabolism in children and young adults with classic 21HD, which could predict early atherogenesis. PATIENTS AND METHODS: Twenty-seven Caucasian patients with classic 21HD (4-31 years); 27 sex-, age- and BMI-matched controls. Clinical parameters, hormonal status and genotype were assessed in all patients. Lipid parameters, including relative (%) and absolute (mg/dl) small-dense low-density lipoproteins subfractions (sd-LDL) were measured in patients and controls. Oral glucose tolerance tests were performed in both groups. RESULTS: sd-LDL (%) was significantly higher in patients than controls (39.7 +/- 5.9 vs. 35.5 +/- 5.7%; p = 0.008). The same applies for absolute sd-LDL (mg/dl) (42.6 +/- 11.9 vs. 36.4 +/- 7.5; p = 0.029). HDL-cholesterol was lower in patients (p = 0.032). Fasting glucose and insulin were significantly higher in patients. Similar differences were noticed for HOMA-IR (p = 0.001), IRI (p = 0.001) and HOMA-B (p = 0.002). IRI correlated directly and significantly with the total hydrocortisone dose and the duration of treatment. Fasting glucose correlated with absolute sd-LDL. No obvious differences were seen between clinical forms or genotype groups. CONCLUSIONS: Substitution therapy should be adapted particularly at young ages to prevent early atherogenesis and cardiovascular risk in later life.

Baseline characteristics and outcome in Romanian patients with Gaucher disease type 1.

BACKGROUND/AIM: To present clinical and genetic characteristics of all Romanian patients with Gaucher disease type 1, in whom specific diagnosis has been confirmed by enzymatic and molecular methods and to analyze their outcome with and without enzymatic replacement therapy (ERT). PATIENTS, METHODS: There are fifty patients (F/M - 1.63/1) with Gaucher disease type 1. Clinical status, haemoglobin, thrombocytes, hepatic/splenic volume, bone mineral density and severity score were assessed at baseline and every six months thereafter. Thirty-nine patients (78%) received imiglucerase (44.4+/-13.6 U/kg/2 weeks) for 3.1+/-1.4 years. RESULTS: Based on general prevalence data, our group represents 22.7% of the expected total number of patients with Gaucher disease type 1 in Romania. Mean age was 15.5 years at clinical onset and 28.9 years at confirmation of diagnosis. The genotype N370S/L444P was frequent in our group (35.9% of alleles). Anaemia, thrombocytopenia, splenomegaly and bone disease were present at 38%, 70%, 100% and 84%, respectively. Mean values for haemoglobin, thrombocytes, hepatic volume and chitotriosidase normalized after 0.5, 1.5, 2.5 and 3 years of ERT, respectively. Splenomegaly regressed from 14.4 x N (normal) to 3.06 x N over four years of treatment. Bone disease was ameliorated under ERT, yet bone mineral density worsened in patients treated with 30 U/kg/2 weeks. CONCLUSIONS: The genotype N370S/L444P is frequent in our patients, in line with the severe phenotypes. ERT improved haematological parameters and visceromegaly, without a clear benefit for bone mineral density. To attain therapeutic goals, an early treatment start with optimal dosage is mandatory.