title: A prospective study validating a clinical scoring system and demonstrating phenotypical-genotypical correlations in Silver-Russell syndrome.
abstract: BACKGROUND
  Multiple clinical scoring systems have been proposed for Silver-Russell syndrome (SRS). Here we aimed to test a clinical scoring system for SRS and to analyse the correlation between (epi)genotype and phenotype.
  
  
  METHODS
  Sixty-nine patients were examined by two physicians. Clinical scores were generated for all patients, with a new, six-item scoring system: (1) small for gestational age, birth length and/or weight ≤-2SDS, (2) postnatal growth retardation (height ≤-2SDS), (3) relative macrocephaly at birth, (4) body asymmetry, (5) feeding difficulties and/or body mass index (BMI) ≤-2SDS in toddlers; (6) protruding forehead at the age of 1-3 years. Subjects were considered to have likely SRS if they met at least four of these six criteria. Molecular investigations were performed blind to the clinical data.
  
  
  RESULTS
  The 69 patients were classified into two groups (Likely-SRS (n=60), Unlikely-SRS (n=9)). Forty-six Likely-SRS patients (76.7%) displayed either 11p15 ICR1 hypomethylation (n=35; 58.3%) or maternal UPD of chromosome 7 (mUPD7) (n=11; 18.3%). Eight Unlikely-SRS patients had neither ICR1 hypomethylation nor mUPD7, whereas one patient had mUPD7. The clinical score and molecular results yielded four groups that differed significantly overall and for individual scoring system factors. Further molecular screening led identifying chromosomal abnormalities in Likely-SRS-double-negative and Unlikely-SRS groups. Four Likely-SRS-double negative patients carried a DLK1/GTL2 IG-DMR hypomethylation, a mUPD16; a mUPD20 and a de novo 1q21 microdeletion.
  
  
  CONCLUSIONS
  This new scoring system is very sensitive (98%) for the detection of patients with SRS with demonstrated molecular abnormalities. Given its clinical and molecular heterogeneity, SRS could be considered as a spectrum.
authors.affiliation: INSERM, UMR_S 938, CDR Saint-Antoine, Paris, France Sorbonne Universités, UPMC Univ Paris 06, UMR_S 938, CDR Saint-Antoine, Paris, France Department of Pediatric Endocrinology, APHP, Armand Trousseau Hospital, Paris, France Epigenetics Programme, The Babraham Institute, Cambridge, UK.
authors.forename: Salah
authors.initials: S
authors.lastname: Azzi
authors.affiliation: MAGIC Foundation, RSS/SGA Research & Education Fund, Oak Park, Illinois, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Salem
authors.affiliation: INSERM, UMR_S 938, CDR Saint-Antoine, Paris, France Sorbonne Universités, UPMC Univ Paris 06, UMR_S 938, CDR Saint-Antoine, Paris, France Department of Pediatric Endocrinology, APHP, Armand Trousseau Hospital, Paris, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Thibaud
authors.affiliation: AP-HP, Hôpital Trousseau, Service de Génétique et d'Embryologie Médicales, Paris, France.
authors.forename: Sandra
authors.initials: S
authors.lastname: Chantot-Bastaraud
authors.affiliation: Department of Psychiatry and Biobehavioral Sciences, Semel Institute, University of California, Los Angeles, California, USA.
authors.forename: Eli
authors.initials: E
authors.lastname: Lieber
authors.affiliation: INSERM, UMR_S 938, CDR Saint-Antoine, Paris, France Sorbonne Universités, UPMC Univ Paris 06, UMR_S 938, CDR Saint-Antoine, Paris, France Department of Pediatric Endocrinology, APHP, Armand Trousseau Hospital, Paris, France.
authors.forename: Irène
authors.initials: I
authors.lastname: Netchine
authors.affiliation: Department of Pediatrics, Ichan School of Medicine at Mount Sinai, New York, New York, USA.
authors.forename: Madeleine D
authors.initials: MD
authors.lastname: Harbison
mesh_terms: D001724:Birth Weight / Q000502:physiology; D015992:Body Mass Index; D005546:Forehead / Q000002:abnormalities; D005838:Genotype; D006128:Growth / Q000502:physiology; D006801:Humans; D058627:Megalencephaly / Q000473:pathology; D010641:Phenotype; D011446:Prospective Studies; D012107:Research Design / Q000592:standards*; D056730:Silver-Russell Syndrome / Q000235:genetics* / Q000473:pathology*
keywords: Clinical scoring system; ICR1 11p15 hypomethylation and mUPD7; Russell Silver Syndrome; Silver Russell Spectrum; phenotypic-genotypic correlation