title: Neonatal hypocalcemia, neonatal seizures, and intellectual disability in 22q11.2 deletion syndrome.
abstract: OBJECTIVE
  Hypocalcemia is a common endocrinological condition in 22q11.2 deletion syndrome. Neonatal hypocalcemia may affect neurodevelopment. We hypothesized that neonatal hypocalcemia would be associated with rare, more severe forms of intellectual disability in 22q11.2 deletion syndrome.
  
  
  METHODS
  We used a logistic regression model to investigate potential predictors of intellectual disability severity, including neonatal hypocalcemia, neonatal seizures, and complex congenital heart disease, e.g., interrupted aortic arch, in 149 adults with 22q11.2 deletion syndrome. Ten subjects had moderate-to-severe intellectual disability.
  
  
  RESULTS
  The model was highly significant (P < 0.0001), showing neonatal seizures (P = 0.0018) and neonatal hypocalcemia (P = 0.047) to be significant predictors of a more severe level of intellectual disability. Neonatal seizures were significantly associated with neonatal hypocalcemia in the entire sample (P < 0.0001), regardless of intellectual level. There was no evidence for the association of moderate-to-severe intellectual disability with other factors such as major structural brain malformations in this sample.
  
  
  CONCLUSIONS
  The results suggest that neonatal seizures may increase the risk for more severe intellectual deficits in 22q11.2 deletion syndrome, likely mediated by neonatal hypocalcemia. Neonatal hypocalcemia often remains unrecognized until the postseizure period, when damage to neurons may already have occurred. These findings support the importance of early recognition and treatment of neonatal hypocalcemia and potentially neonatal screening for 22q11.2 deletions.
authors.affiliation: Clinical Genetics Research Program, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.
authors.forename: Evelyn Ning Man
authors.initials: EN
authors.lastname: Cheung
authors.affiliation: 1] Neuroscience Department, Centre for Addiction and Mental Health, Toronto, Ontario, Canada [2] Department of Medicine, University of Toronto, Toronto, Ontario, Canada [3] Department of Pharmacology, University of Toronto, Toronto, Ontario, Canada [4] Dalglish Family Hearts and Minds Clinic, University Health Network, Toronto, Ontario, Canada.
authors.forename: Susan R
authors.initials: SR
authors.lastname: George
authors.affiliation: 1] Dalglish Family Hearts and Minds Clinic, University Health Network, Toronto, Ontario, Canada [2] Division of Neurology, Krembil Neuroscience Centre, Epilepsy Genetics Program, Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Danielle M
authors.initials: DM
authors.lastname: Andrade
authors.affiliation: 1] Clinical Genetics Research Program, Centre for Addiction and Mental Health, Toronto, Ontario, Canada [2] Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Eva W C
authors.initials: EW
authors.lastname: Chow
authors.affiliation: 1] Department of Medicine, University of Toronto, Toronto, Ontario, Canada [2] Dalglish Family Hearts and Minds Clinic, University Health Network, Toronto, Ontario, Canada [3] Division of Cardiology, Department of Medicine, University Health Network, Toronto, Ontario, Canada [4] Toronto Congenital Cardiac Centre for Adults, Toronto General Hospital, Toronto, Ontario, Canada [5] Obstetric Medicine, Mount Sinai Hospital, Toronto, Ontario, Canada.
authors.forename: Candice K
authors.initials: CK
authors.lastname: Silversides
authors.affiliation: 1] Clinical Genetics Research Program, Centre for Addiction and Mental Health, Toronto, Ontario, Canada [2] Dalglish Family Hearts and Minds Clinic, University Health Network, Toronto, Ontario, Canada [3] Division of Neurology, Krembil Neuroscience Centre, Epilepsy Genetics Program, Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada [4] Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada [5] Division of Cardiology, Department of Medicine, University Health Network, Toronto, Ontario, Canada [6] Toronto Congenital Cardiac Centre for Adults, Toronto General Hospital, Toronto, Ontario, Canada [7] Obstetric Medicine, Mount Sinai Hospital, Toronto, Ontario, Canada [8] Department of Psychiatry, University Health Network, Toronto, Ontario, Canada.
authors.forename: Anne S
authors.initials: AS
authors.lastname: Bassett
mesh_terms: D004062:DiGeorge Syndrome / Q000175:diagnosis / Q000503:physiopathology*; D005260:Female; D006801:Humans; D006996:Hypocalcemia / Q000503:physiopathology*; D007231:Infant, Newborn; D008607:Intellectual Disability / Q000503:physiopathology*; D016015:Logistic Models; D008297:Male; D015997:Neonatal Screening; D012307:Risk Factors; D012640:Seizures / Q000503:physiopathology*; D055815:Young Adult