Loretta Thomaidis

A substitution involving the NLGN4 gene associated with autistic behavior in the Greek population.

Autism is a neurodevelopmental disorder characterized by clinical, etiologic, and genetic heterogeneity. During the last decade, predisposing genes and genetic loci were under investigation. Recently, mutations in two X-linked neuroligin genes, neuroligin 3 (NLGN3) and neuroligin 4 (NLGN4), have been implicated in the pathogenesis of autism. In our ongoing survey, we screened 169 patients with autism for mutations linked with autism. In the preliminary study of specific exons of NLGN3 and NLGN4 genes, we identified the p.K378R substitution (c.1597 A > G) in exon 5 of the NLGN4 gene in a patient who was found to have mild autism and normal IQ at 3 years of age. The same mutation has previously been found in a patient with autism. It is important that, for the first time, a specific mutation in neuroligins is confirmed in a molecular screen in another homogeneous ethnic population. This finding further contributes to consideration of neuroligins as probable candidate genes for future molecular genetic studies, suggesting that a defect of synaptogenesis may predispose to autism.

The use of array-CGH in a cohort of Greek children with developmental delay

BackgroundThe genetic diagnosis of mental retardation (MR) is difficult to establish and at present many cases remain undiagnosed and unexplained. Standard karyotyping has been used as one of the routine techniques for the last decades. The implementation of Array Comparative Genomic Hybridization (array-CGH) has enabled the analysis of copy number variants (CNVs) with high resolution. Major cohort studies attribute 11% of patients with unexplained mental retardation to clinically significant CNVs. Here we report the use of array-CGH for the first time in a Greek cohort. A total of 82 children of Greek origin with mean age 4.9 years were analysed in the present study. Patients with visible cytogenetic abnormalities ascertained by standard karyotyping as well as those with subtelomeric abnormalities determined by Multiplex Ligation-dependent Probe Amplification (MLPA) or subtelomeric FISH had been excluded.ResultsFourteen CNVs were detected in the studied patients. In nine patients (11%) the chromosomal aberrations were inherited from one of the parents. One patients showed two duplications, a 550 kb duplication in 3p14.1 inherited from the father and a ~1.1 Mb duplication in (22)(q13.1q13.2) inherited from the mother. Although both parents were phenotypically normal, it cannot be excluded that the dual duplication is causative for the patients clinical profile including dysmorphic features and severe developmental delay. Furthermore, three de novo clinically significant CNVs were detected (3.7%). There was a ~6 Mb triplication of 18q21.1 in a girl 5 years of age with moderate MR and mild dysmorphic features and a ~4.8 Mb duplication at (10)(q11.1q11.21) in a 2 years old boy with severe MR, multiple congenital anomalies, severe central hypotonia, and ataxia. Finally, in a 3 year-old girl with microcephaly and severe hypotonia a deletion in (2)(q31.2q31.3) of about ~3.9 Mb was discovered. All CNVs were confirmed by Fluorescence in situ hybridization (FISH). For the remaining 9 patients the detected CNVs (inherited duplications or deletions of 80 kb to 800 kb in size) were probably not associated with the clinical findings.ConclusionsGenomic microarrays have within the recent years proven to be a highly useful tool in the investigation of unexplained MR. The cohorts reported so far agree on an around 11% diagnostic yield of clinically significant CNVs in patients with unexplained MR. Various publicly available databases have been created for the interpretation of identified CNVs and parents are analyzed in case a rare CNV is identified in the child. We have conducted a study of Greek patients with unexplained MR and confirmed the high diagnostic value of the previous studies. It is important that the technique becomes available also in less developed countries when the cost of consumables will be reduced.

Does Early Intervention Work? A Controlled Trial.

The study described herein is a controlled trial on the efficacy of a well-structured early intervention program for children with clearly marked biological impairments. Twenty-four children were placed into two matched groups in terms of age, sex, type of disability, functional level, and family socioeconomic status. The treatment group received a weekly educational visit from early intervention advisors for 2 years while the control group received no form of intervention due to lack of provision in the remote provincial towns and islands where the families were living. Four assessments using Griffiths developmental checklists were made in both groups: an initial assessment, a first year assessment, a second year assessment, and 8 months after the end of the program. The results are significantly encouraging. They show remarkable gains for the treatment group both in terms of overall functioning level and in terms of acceleration in different domains of development. The control group remained more or less stable. Gains for the treatment group continued to occur, but at a lesser rate, through the second year. Moreover, gains in development for the treatment group were not lost 8 months after the end of the program. Although the sample is rather small, there are clear indications that early intervention projects that treat children having biologically based disabilities are effective.

Cognitive and psychosocial development of HIV pediatric patients receiving highly active anti-retroviral therapy: a case-control study

BackgroundThe psychosocial development of pediatric HIV patients has not been extensively evaluated. The study objectives were to evaluate whether emotional and social functions are differentially associated with HIV-related complications.MethodsA matched case-control study design was conducted. The case group (n = 20) consisted of vertically infected children with HIV (aged 3-18 years) receiving HAART in Greece. Each case was matched with two randomly selected healthy controls from a school-based population. CNS imaging and clinical findings were used to identify patients with HIV-related neuroimaging abnormalities. The Wechsler Intelligence Scale III and Griffiths Mental Abilities Scales were applied to assess cognitive abilities. The age specific Strengths and Difficulties Questionnaire was used to evaluate emotional adjustment and social skills. The Fishers exact test, students t-test, and Wilcoxon rank sum test were used to compare categorical, continuous, and ordinal scores, respectively, of the above scales between groups.ResultsHIV patients without neuroimaging abnormalities did not differ from patients with neuroimaging abnormalities with respect to either age at HAART initiation (p = 0.306) or months of HAART treatment (p = 0.964). While HIV patients without neuroimaging abnormalities had similar cognitive development with their healthy peers, patients with neuroimaging abnormalities had lower mean General (p = 0.027) and Practical (p = 0.042) Intelligence Quotient scores. HIV patients without neuroimaging abnormalities had an increased likelihood of both Abnormal Emotional Symptoms (p = 0.047) and Hyperactivity scores (p = 0.0009). In contrast, HIV patients with neuroimaging abnormalities had an increased likelihood of presenting with Abnormal Peer Problems (p = 0.033).ConclusionsHIV patients without neuroimaging abnormalities are more likely to experience maladjustment with respect to their emotional and activity spheres, while HIV patients with neuroimaging abnormalities are more likely to present with compromised social skills. Due to the limited sample size and age distribution of the study population, further studies should investigate the psychosocial development of pediatric HIV patients following the disclosure of their condition.

A patient with partial trisomy 21 and 7q deletion expresses mild Down syndrome phenotype

BACKGROUND Down syndrome (DS) is the most common aneuploidy in live-born individuals and it is well recognized with various phenotypic expressions. Although an extra chromosome 21 is the genetic cause for DS, specific phenotypic features may result from the duplication of smaller regions of the chromosome and more studies need to define genotypic and phenotypic correlations. CASE REPORT We report on a 26 year old male with partial trisomy 21 presenting mild clinical symptoms relative to DS including borderline intellectual disability. In particular, the face and the presence of hypotonia and keratoconus were suggestive for the DS although the condition remained unnoticed until his adult age array comparative genomic hybridization (aCGH) revealed a 10.1 Mb duplication in 21q22.13q22.3 and a small deletion of 2.2 Mb on chromosomal band 7q36 arising from a paternal translocation t(7;21). The 21q duplication encompasses the gene DYRK1. CONCLUSION Our data support the evidence of specific regions on distal 21q whose duplication results in phenotypes recalling the typical DS face. Although the duplication region contains DYRK1, which has previously been implicated in the causation of DS, our patient has a borderline IQ confirming that their duplication is not sufficient to cause the full DS phenotype.

Psychomotor development of children born after preimplantation genetic diagnosis and parental stress evaluation

BackgroundThe increasing number of children conceived following preimplantation genetic diagnosis (PGD) necessitates the evaluation of their motor and cognitive development. The primary study objective was to evaluate the physical, developmental, and neurological outcome of children born after PGD in Greece. In addition, the secondary study objective was to compare the stress levels regarding parental roles between parents of PGD children and those of naturally conceived children.MethodsA cross-sectional study design was applied. The study population consisted of 31 children (aged 2 months to 7.5 years) born after PGD analysis and their parents. The developmental evaluation of children included a detailed physical evaluation and cognitive assessment with the Bayley Scales of Infant Development. The parent stress index was applied to evaluate comparative parental stress levels between those parents of PGD children and those of naturally conceived healthy children.ResultsHigh rates of caesarean deliveries, increased incidence of prematurity, multiples and low-birth weight were observed among the 31 PGD children. Overall, 24 of the 31 PGD children had cognitive skills within normal range [general developmental quotient (GDQ): 86–115], while 6 children had lower levels of cognitive skills (GDQ<85). With regard to parental stress, PGD parents reported lower levels of parenting stress as compared to parents of naturally conceived children (P<0.01).ConclusionsThe enhanced frequency of poor cognitive and motor skills as well as low parental stress necessitates early detection and intervention for developmental delays among PGD children.

Tetrasomy 9p Mosaicism Associated with a Normal Phenotype in Two Cases

Tetrasomy 9p is a rare chromosomal syndrome and about 30% of known cases exhibit mosaicism. Approximately 50 of the reported cases with tetrasomy 9p mosaicism show a characteristic facial appearance, growth failure, and developmental delay. However, 3 patients with mosaicism for isochromosome 9p and a normal phenotype have also been reported. We report 2 additional cases of clinically normal young females with tetrasomy 9p mosaicism, one of whom also exhibited X chromosome aneuploidy mosaicism leading to an overall of 6 different cell lines. STR analysis performed on this complex mosaic case indicated that the extra isochromosome was of maternal origin while the X chromosome aneuploidy was of paternal origin, indicating a postzygotic event.

Detailed molecular and clinical investigation of a child with a partial deletion of chromosome 11 (Jacobsen syndrome)

BackgroundJacobsen syndrome (JBS) is a rare chromosomal disorder leading to multiple physical and mental impairment. This syndrome is caused by a partial deletion of chromosome 11, especially subband 11q24.1 has been proven to be involved. Clinical cases may easily escape diagnosis, however pancytopenia or thrombocytopenia may be indicative for JBS.ResultsWe report a 7.5 years old boy presenting with speech development delay, hearing impairment and abnormal platelet function. High resolution SNP oligonucleotide microarray analysis revealed a terminal deletion of 11.4 Mb in size, in the area 11q24.1-11qter. This specific deletion encompasses around 170 genes. Other molecular techniques such as fluorescence in situ hybridization and multiplex ligation-dependent probe amplification were used to confirm the array-result.DiscussionOur results suggest that the identification and detailed analysis of similar patients with abnormal platelet function and otherwise mild clinical features will contribute to identification of more patients with 11q deletion and JBS.

Deletion 2q31.2-q31.3 in a 4-year-old girl with microcephaly and severe mental retardation†

Deletion 2q31.2-q31.3 in a 4-Year-Old Girl With Microcephaly and Severe Mental Retardation Emmanouil Manolakos,* Annalisa Vetro, Konstantinos Kefalas, Loretta Thomaidis, Georgios Aperis, Sotirios Sotiriou, George Kitsos, Martina Merkas, Stavros Sifakis, Ioannis Papoulidis, Thomas Liehr, Orsetta Zuffardi, and Michael B. Petersen Bioiatriki S.A., Laboratory of Genetics, Athens, Greece Dipartimento di Patologia Umana ed Ereditaria, Universita di Pavia, Pavia, Italy Department of Paediatrics, University of Athens, Aglaia Kyriakou Children’s Hospital, Athens, Greece Nephrology Clinic, General Hospital Rhodes, Agioi Apostoloi, Rhodes, Greece Department of Embryology, University of Thessaly, Larissa, Greece Department of Ophthalmology, University of Ioannina, Ioannina, Greece Jena University Hospital, Institute of Human Genetics and Anthropology, Jena, Germany Department of Obstetrics and Gynecology, University Hospital of Heraklion, Crete, Greece Eurogenetica, Laboratory of Genetics, Athens, Greece Department of Genetics, Institute of Child Health, Athens, Greece

Predictors of severity and outcome of global developmental delay without definitive etiologic yield: a prospective observational study

BackgroundAlthough several determinants of global developmental delay (GDD) have been recognized, a significant number of children remain without definitive etiologic diagnosis. The objective of this study was to assess the effect of various prenatal and perinatal factors on the severity and outcome of developmental delay without definitive etiologic yield.MethodsFrom March 2008 to February 2010, 142 children with developmental quotient (DQ) <70 and without definitive etiologic diagnosis, were included. Prenatal and perinatal risk factors known to be associated with disordered neonatal brain function were identified. Participants underwent a thorough investigation, an individualized habilitation plan was recommended, and the children were followed-up regularly for a period of 2 < years. The effect of prenatal and perinatal risk factors on the severity and outcome of GDD was assessed by regression analysis.ResultsThe mean age at enrolment was 31 ± 12 < months, and the mean DQ 52.2 ± 11.4. Prematurity and intrauterine growth restriction (IUGR) were found to be independently associated with lower DQ values. The mean DQ after the 2-year follow-up was 62.5 ± 12.7, and the DQ difference from the enrollment 10.4 ± 8.9 (median 10; range-10 to 42). DQ improvement (defined as a DQ difference?≥?median) was noted in 52.8% of the children. IUGR, low socio-economic status, and poor compliance to habilitation plan were found to be independently associated with poorer developmental outcomes.ConclusionsPrematurity and IUGR were found to be significantly and independently related to the severity of GDD in cases without definitive etiologic yield. Poorer 2-year developmental outcome was associated with IUGR, low socioeconomic status and non compliance to habilitation plan. Prematurity was a significant determinant of the outcome only in association with the above mentioned factors.