Pallister-Killian Syndrome versus Trisomy 12p-A Clinical Study of 5 New Cases and a Literature Review.

Pallister-Killian syndrome (PKS) is a rare, sporadic disorder defined by a characteristic dysmorphic face, pigmentary skin anomalies, intellectual disability, hypotonia, and seizures caused by 12p tetrasomy due to an extra isochromosome 12p. We present three cases of PKS and two cases of trisomy 12p to illustrate and discuss features rarely cited in the literature, present certain particularities that not yet been cited, and analyze the differences between entities. Moreover, we present alternative methods of diagnosis that could be easily used in daily practice. Features not yet or rarely reported in PKS literature include marked excess of hair on the forehead and ears in the first months of life, a particular eye disorder (abnormal iris color with pointed pupil), connective tissue defects, repeated episodes of infection and autonomic dysfunction, endocrine malfunction as a possible cause of postnatal growth deficit, more complex sensory impairments, and mild early myoclonic jerks. After performing different combinations of tests, we conclude that MLPA (follow-up kit P230-B1) or array CGH using DNA extracted from a buccal swab is a reliable method of diagnosis in PKS and we recommend either one as a first intention diagnostic test. In cases without major defects associated (suspicion trisomy 12p), subtelomeric MLPA should be performed first.

Autism and severe clinical phenotype in a patient with 8p21.2p11.21 deletion: Case report and literature review.

Interstitial 8p deletions were previously described, in literature and databases, in approximately 30 patients with neurodevelopmental disorders. We report on a novel patient with a 8p21.2p11.21 deletion presenting a clinical phenotype that includes severe intellectual disability, microcephaly, epilepsy, and autism, the latter having been rarely associated with this genetic defect.

Monitoring Methylmalonic Aciduria by NMR Urinomics.

The paper reports on monitoring methylmalonic aciduria (MMA)-specific and non-specific metabolites via NMR urinomics. Five patients have been monitored over periods of time; things involved were diet, medication and occasional episodes of failing to comply with prescribed diets. An extended dataset of targeted metabolites is presented, and correlations with the type of MMA are underlined. A survey of previous NMR studies on MMA is also presented.

Haploinsufficiency of BAZ1B contributes to Williams syndrome through transcriptional dysregulation of neurodevelopmental pathways.

Williams syndrome (WS) is a neurodevelopmental disorder caused by a genomic deletion of ∼28 genes that results in a cognitive and behavioral profile marked by overall intellectual impairment with relative strength in expressive language and hypersocial behavior. Advancements in protocols for neuron differentiation from induced pluripotent stem cells allowed us to elucidate the molecular circuitry underpinning the ontogeny of WS. In patient-derived stem cells and neurons, we determined the expression profile of the Williams-Beuren syndrome critical region-deleted genes and the genome-wide transcriptional consequences of the hemizygous genomic microdeletion at chromosome 7q11.23. Derived neurons displayed disease-relevant hallmarks and indicated novel aberrant pathways in WS neurons including over-activated Wnt signaling accompanying an incomplete neurogenic commitment. We show that haploinsufficiency of the ATP-dependent chromatin remodeler, BAZ1B, which is deleted in WS, significantly contributes to this differentiation defect. Chromatin-immunoprecipitation (ChIP-seq) revealed BAZ1B target gene functions are enriched for neurogenesis, neuron differentiation and disease-relevant phenotypes. BAZ1B haploinsufficiency caused widespread gene expression changes in neural progenitor cells, and together with BAZ1B ChIP-seq target genes, explained 42% of the transcriptional dysregulation in WS neurons. BAZ1B contributes to regulating the balance between neural precursor self-renewal and differentiation and the differentiation defect caused by BAZ1B haploinsufficiency can be rescued by mitigating over-active Wnt signaling in neural stem cells. Altogether, these results reveal a pivotal role for BAZ1B in neurodevelopment and implicate its haploinsufficiency as a likely contributor to the neurological phenotypes in WS.

Microduplications of 3p26.3p26.2 containing CRBN gene in patients with intellectual disability and behavior abnormalities.

We report on the clinical data and molecular cytogenetic findings in three unrelated patients presenting with intellectual disability and behavior abnormalities. An overlapping microduplication involving 3p26.2-26.3 was identified in these patients. All three aberrations were confirmed and proven to be parentally inherited. The sizes of the duplications were different, with a common minimal region of 423,754 bp containing two genes - TRNT1 and CRBN. Here, we hypothesize that the copy number gain of CRBN gene might be responsible for developmental delay/intellectual disability.

Diagnostic approach of angelman syndrome.

BACKGROUND: Angelman syndrome (AS) is a genetic condition, characterized by severe mental retardation, ataxic gait, severe speech delay, dysmorphic features, abnormal behaviour, movement disorder. It is caused by a variety of genetic mechanisms which all interfere with expression of the UBE3A gene on chromosome 15q11-13. OBJECTIVES: To present our experience regarding diagnosis of children with Angelman syndrome. MATERIAL AND METHODS: 15 children were clinically and genetically diagnosed with AS in the Department of Pediatric Neurology of the "Prof. Dr. Alex. Obregia" Clinical Hospital. In all cases, diagnosis of AS was made by the clinical criteria. The clinical evaluation focused on the patient history, a general examination, dysmorphological evaluation, a neurological examination, psychological evaluation, and paraclinical tests. RESULTS: All patients from this study presented the characteristic facial features and the characteristic behavior phenotype. Psychomotor development was delayed in all children, most of cases (73%) presenting with sever mental retardation. Epileptic seizures were observed in all patients with microdeletion, the partial seizures being the most frequent type. EEG in all children showed the characteristic pattern for AS. CONCLUSIONS: Angelman syndrome is a rare and severe neurodevelopmental disorder, with a complex clinical picture. There are some characteristic facial features, which, in association with hypopigmentation, happy disposition, jerky movements, and ataxia in a child with psychomotor delay should raise the strong suspicion of AS.

3p interstitial deletion: novel case report and review.

3p interstitial deletions have emerged in recent years as a new cause of neurodevelopmental delay and intellectual disability. Since the first report of this condition in 1979, 16 cases have been described in the literature, delineating it as a presumptive syndrome. Here, we add a novel case presenting severely delayed neurodevelopment and psychomotor development; facial dysmorphism (square facies, broad forehead, short palpebral fissures, epicanthic folds, broad nasal bridge, and low-set malformed ears); cerebral, cardiac, and genital malformations; hand and feet anomalies; sacral sinus; and hearing impairment. Genetic investigations revealed a del(3)(p12.3p14.1) of 12.5 Mb, including 31 ORFs, among which ROBO2, PDZRN3, MITF, and FOXP1 are known to act in neurodevelopment. The clinical features of our patient are compared with those previously reported in the literature, thus providing further support for the delineation of the 3p interstitial deletion syndrome.

Atypical presentations of 22q11.2 deletion syndrome: explaining the genetic defects and genome architecture.

22q11.2 deletion syndrome, the most common microdeletion syndrome, exhibits a broad range of phenotypes, implying a cumbersome diagnosis due to atypical or paucisymptomatic presentations. We present two atypical cases of 22q11.2 deletion syndrome and suggest a preferential occurrence of the breakpoints in regions poor in repetitive elements of SINE/Alu family.

Variant e19a2 BCR-ABL1 fusion transcript in typical chronic myeloid leukemia.

BACKGROUND: The landmark of chronic myeloid leukemia (CML) is the reciprocal translocation t(9;22)(q34;q11), generating the BCR-ABL1 hybrid gene. About 15 types of fusion transcripts have been described to date. Among the rarer types, e19a2 was described for the first time in 1990 by Saglio et al. (1). Here, we report on a new case of CML with the e19a2 transcript. METHODS: A 38 year-old male patient was referred for genetic investigations with a clinical diagnosis of CML. Karyotyping and molecular genetics investigations (reverse-transcription and sequencing) were performed. RESULTS: t(9;22)(q34;q11.2) was found in 100% of metaphases and the patient's BCR-ABL1 fusion gene showed the rare variant transcript e19a3 with no sequence alterations. CONCLUSIONS: CML with e19a2 fusion transcript is a rare disease with a large variety of clinical manifestations and unclear biological significance. Adding new cases to the current knowledge will contribute to the understanding of its mechanisms and the clarification of its prognosis.

Methylenetetrahydrofolate dehydrogenase (MTHFD) enzyme polymorphism as a maternal risk factor for trisomy 21: a clinical study.

Recent reports linking Down syndrome (DS) to maternal polymorphism at the methylenetetrahydrofolate dehydrogenase (MTHFD) locus have generated a great interest among investigators in the field. In the current study, we examine one genetic polymorphism involved in homocysteine/folate pathway as a risk factor for DS in a Romanian urban-area women cohort. Our results show that the frequencies of MTHFD1 alleles, as well as the frequencies of MTHFD11958 genotypes (GG, GA, AA, GA+AA) do not correlate with DS pregnancies, demonstrating no difference between the case and control groups, as opposed to the findings of Scala et al. (2006) on an Italian cohort.

18q deletion syndrome - A case report.

We report on a 3 years old boy with severe mental retardation, hypotonia, deafness, cerebral dysmyelination, low levels of immunoglobulin A and dysmorphic features, bearing a distal deletion of 18q: 18q21-qter. Karyotype analysis by GTG banding was performed, revealing a deletion of the distal fragment of chromosome 18q, ranging from band q21 to qter, later confirmed by Fluorescence In Situ Hybridization (FISH). Whole chromosome painting for chromosome 18 ruled out any cryptic rearrangements involving other chromosomes. An attempted therapy with growth hormone did not bring any improvement and was discontinued due to an unexplained febrile episode and overall regress of the patient.

RFC - 1 Gene Polymorphism and the Risk of Down Syndrome in Romanian Population.

BACKGROUND AND AIMS: There is evidence that the polymorphisms of the genes involved in folate metabolism may be associated with higher risk of Down syndrome (DS) pregnancy. The aim of the present study was to investigate the effect of A80G polymorphism in reduced folate carrier 1 (RFC1) gene on the maternal risk for DS. METHODS: In our study, twenty-two DS mothers and forty-two mothers who had no children with DS were evaluated. Genomic DNA was isolated from whole peripheral blood collected on EDTA, using peqGOLD blood DNA mini kit (ATP Biotech) following the manufacturer's instructions. RESULTS: The results show that the frequencies of RFC1 alleles, as well as the frequencies of RFC1 A80G genotypes (GG, GA, AA, GA+AA) do not correlate with DS pregnancies, demonstrating no difference between the case and control groups. CONCLUSIONS: In the present study, we did not find any statistically significant association between RFC-1 polymorphic genotype and history of DS pregnancies; thus, the relationship between RFC-1 polymorphism and DS appears to be only a supposition and the next step in our study is the catamnestic evaluation of our patients with DS babies for two years.

Deletion of the high-affinity cAMP phosphodiesterase encoded by PDE2 affects stress responses and virulence in Candida albicans.

Previously, we have shown that PDE2 is required for hyphal development and cell wall integrity in Candida albicans. In the present study, we have investigated the effects of its deletion by genome-wide transcriptome profiling. Changes in expression levels of genes involved in metabolism, transcription, protein and nucleic acids synthesis, as well as stress responses, cell wall and membrane biogenesis, adherence and virulence have been observed. By comparing these changes with previously reported transcriptome profiles of pde2Delta mutants of Saccharomyces cerevisiae, as well as cdc35Delta, ras1Delta and efg1Delta mutants of C. albicans, conserved and species-specific cAMP-regulated genes have been identified. The genes whose transcription is altered upon deletion of PDE2 in C. albicans has also allowed us to predict that the pde2Delta mutant would have a defective ability to adhere to, and invade host cells, and an impaired virulence as well as response to different stresses. Using appropriate assays, we have tested these predictions and compared the roles of the high- and low-affinity cAMP phosphodiesterases, Pde2p and Pde1p in stress, adhesion and virulence. We suggest that phosphodiesterases, and in particular the high-affinity cAMP phosphodiesterase encoded by PDE2, have real potential as targets for antifungal chemotherapy.

Mutational analysis of the yeast multidrug resistance ABC transporter Pdr5p with altered drug specificity.

Multidrug resistance ABC transporter Pdr5p of Saccharomyces cerevisiae is particularly important due to its ability to export a wide range of unrelated substrates. To clarify its function, we generated Pdr5p mutants by random mutagenesis and screened for mutants with altered drug specificity in vivo by using 5 drug compounds. Nine point mutations that caused significant changes in drug specificity distributed throughout the length of Pdr5p, namely, in the extracellular, transmembrane or cytoplasmic regions of the transporter. We then investigated their effects upon drug resistance, using 36 chemically related or distinct substrates. From this study, overall geometry of the Pdr5p was suggested to contribute in acquiring the enormous range of drug specificity. Based on their ability to inhibit the growth of the mutant strains, the 36 tested drugs were classified into: drugs to which the mutants responded differently (Group 1), drugs to which all the mutants showed sensitivity (Group 2), and drugs to which all the mutants exhibited resistance (Group 3). The ability of the compounds to be partitioned to the plasma membrane seemed an important factor for recognition by Pdr5p.

Involvement of Saccharomyces cerevisiae Pdr5p ATP-binding cassette transporter in calcium homeostasis.

Deletion of PDR5 gene (Deltapdr5) in Saccharomyces cerevisiae led to increased resistance to calcium. The cellular Ca2+ level in the presence of high calcium as estimated by reporter assay in Deltapdr5 cells was significantly lower than that in wild-type cells. Membrane Pdr5p levels diminished rapidly during incubation with high calcium in a manner dependent on calcineurin and Pep4p, suggesting a feedback regulatory mechanism for Pdr5p abundance.