Browsing by Person "Conti-Ramsden, Gina"

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Homozygous microdeletion of exon 5 in ZNF277 in a girl with specific language impairment.
(Nature Publishing Group, 2014-02) Ceroni, Fabiola; Simpson, Nuala H.; Francks, Clyde; Baird, Gillian; Conti-Ramsden, Gina; Clark, Ann; Bolton, Patrick F.; Hennessy, Elizabeth R.; Donnelly, Peter; Bentley, David R.; Martin, Hilary; Parr, Jeremy; Pagnamenta, Alistair T.; Maestrini, Elena; Bacchelli, Elena; Fisher, Simon E.; Newbury, Dianne F.
Specific language impairment (SLI), an unexpected failure to develop appropriate language skills despite adequate non-verbal intelligence, is a heterogeneous multifactorial disorder with a complex genetic basis. We identified a homozygous microdeletion of 21,379-bp in the ZNF277 gene (NM_021994.2), encompassing exon 5, in an individual with severe receptive and expressive language impairment. The microdeletion was not found in the proband's affected sister or her brother who had mild language impairment. However, it was inherited from both parents, each of whom carries a heterozygous microdeletion and has a history of language problems. The microdeletion falls within the AUTS1 locus, a region linked to autistic spectrum disorders (ASDs). Moreover, ZNF277 is adjacent to the DOCK4 and IMMP2L genes, which have been implicated in ASD. We screened for the presence of ZNF277 microdeletions in cohorts of children with SLI or ASD and panels of control subjects. ZNF277 microdeletions were at an increased allelic frequency in SLI probands (1.1%) compared with both ASD family members (0.3%) and independent controls (0.4%). We performed quantitative RT-PCR analyses of the expression of IMMP2L, DOCK4 and ZNF277 in individuals carrying either an IMMP2L_DOCK4 microdeletion or a ZNF277 microdeletion. Although ZNF277 microdeletions reduce the expression of ZNF277, they do not alter the levels of DOCK4 or IMMP2L transcripts. Conversely, IMMP2L_DOCK4 microdeletions do not affect the expression levels of ZNF277. We postulate that ZNF277 microdeletions may contribute to the risk of language impairments in a manner that is independent of the autism risk loci previously described in this region.
Increased prevalence of sex chromosome aneuploidies in specific language impairment and dyslexia.
(Wiley, 2014-04) Simpson, Nuala H.; Addis, Laura; Brandler, William M.; Slonims, Vicky; Clark, Ann; Watson, Jocelynne; Scerri, Thomas S.; Hennessy, Elizabeth R.; Bolton, Patrick F.; Conti-Ramsden, Gina; Fairfax, Benjamin P.; Knight, Julian C.; Stein, John; Talcott, Joel B.; O'Hare, Anne; Baird, Gillian; Paracchini, Silvia; Fisher, Simon E.; Newbury, Dianne F.; Consortium, Sli
AIM Sex chromosome aneuploidies increase the risk of spoken or written language disorders but individuals with specific language impairment (SLI) or dyslexia do not routinely undergo cytogenetic analysis. We assess the frequency of sex chromosome aneuploidies in individuals with language impairment or dyslexia. METHOD Genome-wide single nucleotide polymorphism genotyping was performed in three sample sets: a clinical cohort of individuals with speech and language deficits (87 probands: 61 males, 26 females; age range 4 to 23 years), a replication cohort of individuals with SLI, from both clinical and epidemiological samples (209 probands: 139 males, 70 females; age range 4 to 17 years), and a set of individuals with dyslexia (314 probands: 224 males, 90 females; age range 7 to 18 years). RESULTS In the clinical language-impaired cohort, three abnormal karyotypic results were identified in probands (proband yield 3.4%). In the SLI replication cohort, six abnormalities were identified providing a consistent proband yield (2.9%). In the sample of individuals with dyslexia, two sex chromosome aneuploidies were found giving a lower proband yield of 0.6%. In total, two XYY, four XXY (Klinefelter syndrome), three XXX, one XO (Turner syndrome), and one unresolved karyotype were identified. INTERPRETATION The frequency of sex chromosome aneuploidies within each of the three cohorts was increased over the expected population frequency (approximately 0.25%) suggesting that genetic testing may prove worthwhile for individuals with language and literacy problems and normal non-verbal IQ. Early detection of these aneuploidies can provide information and direct the appropriate management for individuals.
Reply to Pembrey et al: 'ZNF277 microdeletions, specific language impairment and the meiotic mismatch methylation (3M) hypothesis'
(2015-09) Ceroni, Fabiola; Simpson, Nuala H.; Francks, Clyde; Baird, Gillian; Conti-Ramsden, Gina; Clark, Ann; Bolton, Patrick F.; Hennessy, Elizabeth R.; Donnelly, Peter; Bentley, David R.; Martin, Hilary; Parr, Jeremy; Pagnamenta, Alistair T.; Maestrini, Elena; Bacchelli, Elena; Fisher, Simon E.; Newbury, Dianne F.