| 1. |
- Lynch, Sally Ann, et al.
(författare)
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The 12q14 microdeletion syndrome : six new cases confirming the role of HMGA2 in growth
- 2011
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Ingår i: European Journal of Human Genetics. - : Springer Science and Business Media LLC. - 1018-4813 .- 1476-5438. ; 19:5, s. 534-539
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Tidskriftsartikel (refereegranskat)abstract
- We report six patients with array deletions encompassing 12q14. Out of a total of 2538 array investigations carried out on children with developmental delay and dysmorphism in three diagnostic testing centres, six positive cases yielded a frequency of 1 in 423 for this deletion syndrome. The deleted region in each of the six cases overlaps significantly with previously reported cases with microdeletions of this region. The chromosomal range of the deletions extends from 12q13.3q15. In the current study, we report overlapping deletions of variable extent and size but primarily comprising chromosomal bands 12q13.3q14.1. Four of the six deletions were confirmed as de novo events. Two cases had deletions that included HMGA2, and both children had significant short stature. Neither case had osteopoikilosis despite both being deleted for LEMD3. Four cases had deletions that ended proximal to HMGA2 and all of these had much better growth. Five cases had congenital heart defects, including two with atrial septal defects, one each with pulmonary stenosis, sub-aortic stenosis and a patent ductus. Four cases had moderate delay, two had severe developmental delay and a further two had a diagnosis of autism. All six cases had significant speech delay with subtle facial dysmorphism.
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| 2. |
- Palomares, Maria, et al.
(författare)
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Characterization of a 8q21.11 Microdeletion Syndrome Associated with Intellectual Disability and a Recognizable Phenotype
- 2011
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Ingår i: American Journal of Human Genetics. - : Elsevier BV. - 0002-9297 .- 1537-6605. ; 89:2, s. 295-301
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Tidskriftsartikel (refereegranskat)abstract
- We report eight unrelated individuals with intellectual disability and overlapping submicroscopic deletions of 8q21.11 (0.66-13.55 Mb in size). The deletion was familial in one and simplex in seven individuals. The phenotype was remarkably similar and consisted of a round face with full cheeks, a high forehead, ptosis, cornea opacities, an underdeveloped alae, a short philtrum, a cupid's bow of the upper lip, down-turned corners of the mouth, micrognathia, low-set and prominent ears, and mild finger and toe anomalies (camptodactyly, syndactyly, and broadening of the first rays). Intellectual disability, hypotonia, decreased balance, sensorineural hearing loss, and unusual behavior were frequently observed. A high-resolution oligonucleotide array showed different proximal and distal breakpoints in all of the individuals. Sequencing studies in three of the individuals revealed that proximal and distal breakpoints were located in unique sequences with no apparent homology. The smallest region of overlap was a 539.7 kb interval encompassing three genes: a Zinc Finger Homeobox 4 (ZFHX4), one microRNA of unknown function, and one nonfunctional pseudogen. ZFHX4 encodes a transcription factor expressed in the adult human brain, skeletal muscle, and liver. It has been suggested as a candidate gene for congenital bilateral isolated ptosis. Our results suggest that the 8q21.11 submicroscopic deletion represents a clinically recognizable entity and that a haploinsufficient gene or genes within the minimal deletion region could underlie this syndrome.
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| 3. |
- Becker, Kerstin, et al.
(författare)
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De novo microdeletions of chromosome 6q14.1-q14.3 and 6q12.1-q14.1 in two patients with intellectual disability : further delineation of the 6q14 microdeletion syndrome and review of the literature
- 2012
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Ingår i: European Journal of Medical Genetics. - : Elsevier BV. - 1769-7212 .- 1878-0849. ; 55:8-9, s. 490-497
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Tidskriftsartikel (refereegranskat)abstract
- Interstitial 6q deletions can cause a variable phenotype depending on the size and location of the deletion. 6q14 deletions have been associated with intellectual disability and a distinct pattern of minor anomalies, including upslanted palpebral fissures with epicanthal folds, a short nose with broad nasal tip, anteverted nares, long philtrum, and thin upper lip. In this study we describe two patients with overlapping 6q14 deletions presenting with developmental delay and characteristic dysmorphism. Molecular karyotyping using array CGH analysis revealed a de novo 8.9 Mb deletion at 6q14.1-q14.3 and a de novo 11.3 Mb deletion at 6q12.1-6q14.1, respectively. We provide a review of the clinical features of twelve other patients with 6q14 deletions detected by array CGH analysis. By assessing all reported data we could not identify a single common region of deletion. Possible candidate genes in 6q14 for intellectual disability might be FILIP1, MYO6, HTR1B, and SNX14.
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| 4. |
- Bena, Frederique, et al.
(författare)
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Molecular and clinical characterization of 25 individuals with exonic deletions of NRXN1 and comprehensive review of the literature
- 2013
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Ingår i: American Journal of Medical Genetics Part B. - : Wiley. - 1552-4841 .- 1552-485X. ; 162B:4, s. 388-403
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Tidskriftsartikel (refereegranskat)abstract
- This study aimed to elucidate the observed variable phenotypic expressivity associated with NRXN1 (Neurexin 1) haploinsufficiency by analyses of the largest cohort of patients with NRXN1 exonic deletions described to date and by comprehensively reviewing all comparable copy number variants in all disease cohorts that have been published in the peer reviewed literature (30 separate papers in all). Assessment of the clinical details in 25 previously undescribed individuals with NRXN1 exonic deletions demonstrated recurrent phenotypic features consisting of moderate to severe intellectual disability (91%), severe language delay (81%), autism spectrum disorder (65%), seizures (43%), and hypotonia (38%). These showed considerable overlap with previously reported NRXN1-deletion associated phenotypes in terms of both spectrum and frequency. However, we did not find evidence for an association between deletions involving the -isoform of neurexin-1 and increased head size, as was recently published in four cases with a deletion involving the C-terminus of NRXN1. We identified additional rare copy number variants in 20% of cases. This study supports a pathogenic role for heterozygous exonic deletions of NRXN1 in neurodevelopmental disorders. The additional rare copy number variants identified may act as possible phenotypic modifiers as suggested in a recent digenic model of neurodevelopmental disorders.
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| 5. |
- Boudry-Labis, Elise, et al.
(författare)
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A novel microdeletion syndrome at 9q21.13 characterised by mental retardation, speech delay, epilepsy and characteristic facial features
- 2013
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Ingår i: European Journal of Medical Genetics. - : Elsevier BV. - 1769-7212 .- 1878-0849. ; 56:3, s. 163-170
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Tidskriftsartikel (refereegranskat)abstract
- The increased use of array-CGH and SNP-arrays for genetic diagnosis has led to the identification of new microdeletion/microduplication syndromes and enabled genotype-phenotype correlations to be made. In this study, nine patients with 9q21 deletions were investigated and compared with four previously Decipher reported patients. Genotype-phenotype comparisons of 13 patients revealed several common major characteristics including significant developmental delay, epilepsy, neuro-behavioural disorders and recognizable facial features including hypertelorism, feature-less philtrum, and a thin upper lip. The molecular investigation identified deletions with different breakpoints and of variable lengths, but the 750 kb smallest overlapping deleted region includes four genes. Among these genes, RORB is a strong candidate for a neurological phenotype. To our knowledge, this is the first published report of 9q21 microdeletions and our observations strongly suggest that these deletions are responsible for a new genetic syndrome characterised by mental retardation with speech delay, epilepsy, autistic behaviour and moderate facial dysmorphy.
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| 6. |
- Demeer, Benedicte, et al.
(författare)
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Duplication 16p13.3 and the CREBBP gene : Confirmation of the phenotype
- 2013
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Ingår i: European Journal of Medical Genetics. - : Elsevier BV. - 1769-7212 .- 1878-0849. ; 56:1, s. 26-31
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Tidskriftsartikel (refereegranskat)abstract
- The introduction of molecular karyotyping technologies into the diagnostic work-up of patients with congenital disorders permitted the identification and delineation of novel microdeletion and microduplication syndromes. Interstitial 16p13.3 duplication, encompassing the CREBBP gene, which is mutated or deleted in the Rubinstein-Taybi syndrome, have been proposed to cause a recognisable syndrome with variable intellectual disability, normal growth, mild facial dysmorphism, mild anomalies of the extremities, and occasional findings such as developmental defects of the heart, genitalia, palate or the eyes. We here report the phenotypic and genotypic delineation of 9 patients carrying a submicroscopic 16p13.3 duplication, including the smallest 16p13.3 duplication reported so far. Careful clinical assessment confirms the distinctive clinical phenotype and also defines frequent associated features : marked speech problems, frequent ocular region involvement with upslanting of the eyes, narrow palpebral fissures, ptosis and strabismus, frequent proximal implantation of thumbs, cleft palate/bifid uvula and inguinal hernia. It also confirms that CREBBP is the critical gene involved in the duplication 16p13.3 syndrome.
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| 7. |
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| 8. |
- Nyström, Anna-Maja, et al.
(författare)
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Investigation of gene dosage imbalances in patients with Noonan syndrome using multiplex ligation-dependent probe amplification analysis
- 2010
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Ingår i: European Journal of Medical Genetics. - : Elsevier BV. - 1769-7212 .- 1878-0849. ; 53:3, s. 117-121
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Tidskriftsartikel (refereegranskat)abstract
- The RAS-MAPK syndromes are a group of clinically and genetically related disorders caused by dysregulation of the RAS-MAPK pathway. A member of this group of disorders, Noonan syndrome (NS), is associated with several different genes within the RAS-MAPK pathway. To date, mutations in PTPN11, SOS1, KRAS, RAF1 and SHOC2 are known to cause NS and a small group of patients harbour mutations in BRAF, MEK1 or NRAS. The majority of the mutations are predicted to cause an up-regulation of the pathway; hence they are gain-of-function mutations. Despite recent advances in gene identification in NS, the genetic aetiology is still unknown in about of patients.To investigate the contribution of gene dosage imbalances of RAS-MAPK-related genes to the pathogenesis of NS, a multiplex ligation-dependent probe amplification (MLPA) assaywas developed. Two probe sets were designed for seven RAS-MAPK-syndrome-related candidate genes: PTPN11, SOS1, RAF1, KRAS, BRAF, MEK1 and MEK2. The probe sets were validated in 15 healthy control individuals and in glioma tumour cell lines. Subsequently, 44 NS patients negative for mutations in known NS-associated genes were screened using the two probe sets. The MLPA results for the patients revealed no gene dosage imbalances. In conclusion, the present results exclude copy number variation of PTPN11, SOS1, RAF1, KRAS, BRAF, MEK1 and MEK2 as a common pathogenic mechanism of NS. The validated and optimised RAS-MAPK probe sets presented here enable rapid high throughput screening of further patients with RAS-MAPK syndromes.
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| 9. |
- Popovici, Cornel, et al.
(författare)
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Whole ARX Gene Duplication is Compatible With Normal Intellectual Development
- 2014
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Ingår i: American Journal of Medical Genetics. Part A. - : Wiley. - 1552-4825 .- 1552-4833. ; 164A:9, s. 2324-2327
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Tidskriftsartikel (refereegranskat)abstract
- We report here on four males from three families carrying de novo or inherited small Xp22.13 duplications including the ARX gene detected by chromosomal microarray analysis (CMA). Two of these males had normal intelligence. Our report suggests that, unlike other XLMR genes like MECP2 and FMR1, the presence of an extra copy of the ARX gene may not be sufficient to perturb its developmental functions. ARX duplication does not inevitably have detrimental effects on brain development, in contrast with the effects of ARX haploinsufficiency. The abnormal phenotype ascribed to the presence of an extra copy in some male patients may have resulted from the effect of another, not yet identified, chromosomal or molecular anomaly, alone or in association with ARX duplication.
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| 10. |
- Schuster, Jens, et al.
(författare)
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Genomic duplications mediate overexpression of lamin B1 in adult-onset autosomal dominant leukodystrophy (ADLD) with autonomic symptoms
- 2011
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Ingår i: Neurogenetics. - : Springer Science and Business Media LLC. - 1364-6745 .- 1364-6753. ; 12:1, s. 65-72
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Tidskriftsartikel (refereegranskat)abstract
- Adult-onset autosomal dominant leukodystrophy (ADLD) with autonomic symptoms features micturition urgency, constipation, erectile dysfunction, and orthostatic hypotension, usually followed by pyramidal signs and ataxia. Peripheral nerve conduction is normal. The disease is often mistaken for multiple sclerosis in the initial phase. There is a characteristic pattern of white matter changes in the brain and spinal cord on magnetic resonance imaging (MRI), mild atrophy of the brain, and a more marked atrophy of the spinal cord. ADLD is associated with duplications of the lamin B1 (LMNB1) gene but the mechanism by which the rearrangement conveys the phenotype is not fully defined. We analyzed four unrelated families segregating ADLD with autonomic symptoms for duplications of the LMNB1 gene. A single nucleotide polymorphism (SNP) array analysis revealed novel duplications spanning the entire LMNB1 gene in probands from each of the four families. We then analyzed the expression of lamin B1 in peripheral leukocytes by Western blot analysis in five patients from two available families. The protein levels of lamin B1 were found significantly increased. These results indicate that the ADLD phenotype associated with LMNB1 duplications is mediated by increased levels of the lamin B1 protein. Furthermore, we show that a molecular diagnosis for ADLD with autonomic symptoms can be obtained by a direct analysis of lamin B1 in peripheral leukocytes.
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