title: Co-occurrence of achondroplasia and Down syndrome: Genotype/phenotype association.
abstract: BACKGROUND
  This report describes the sixth case of an unusual association: Down syndrome with achondroplasia. It also analyzes the effects of both of these disorders on patient phenotype.
  
  
  METHODS
  A male infant was evaluated for Down syndrome. His appearance also suggested a diagnosis of achondroplasia. The child was evaluated by physical examination, radiography, cytogenetic study, and mutation analysis.
  
  
  RESULTS
  Chromosome analysis showed a karyotype of 47,XY,+21 in all 30 cells analyzed. Radiographic examination showed typical findings of achondroplasia, such as disproportionately large skull, shortening of limb segments, and lumbar lordosis. FGFR3 screening showed a heterozygous G1138A mutation.
  
  
  CONCLUSIONS
  The interaction of these two distinct genetic disorders in the same patient produces a phenotype typical of each syndrome with some overlapping signs. This case represents de novo origin of two disorders that both may be parental-age related.
authors.affiliation: Laboratory of Human Genetics and Mutagenesis, Biology Institute, Federal University of Bahia, Barão de Geremoabo, Salvador, Bahia, Brazil. lazevedo@ufba.br
authors.forename: Lilia Maria
authors.initials: LM
authors.lastname: de Azevedo Moreira
authors.forename: Marcos A
authors.initials: MA
authors.lastname: Matos
authors.forename: Patricia P
authors.initials: PP
authors.lastname: Schiper
authors.forename: Acácia F L
authors.initials: AF
authors.lastname: Carvalho
authors.forename: Ivalda C
authors.initials: IC
authors.lastname: Gomes
authors.forename: José C
authors.initials: JC
authors.lastname: Rolemberg
authors.forename: Renata L L
authors.initials: RL
authors.lastname: Ferreira de Lima
authors.forename: Maria B P
authors.initials: MB
authors.lastname: Toralles
mesh_terms: D000130:Achondroplasia / Q000150:complications* / Q000235:genetics / Q000473:pathology; D019943:Amino Acid Substitution; D004314:Down Syndrome / Q000150:complications* / Q000235:genetics / Q000473:pathology / Q000523:psychology; D005838:Genotype; D006801:Humans; D007231:Infant, Newborn; D007621:Karyotyping; D008297:Male; D008423:Maternal Age; D020125:Mutation, Missense; D010331:Paternal Age; D010641:Phenotype; D017354:Point Mutation; D051498:Receptor, Fibroblast Growth Factor, Type 3 / Q000235:genetics*
chemical_list: C496365:FGFR3 protein, human; D051498:Receptor, Fibroblast Growth Factor, Type 3