Partial monosomy 11q and trisomy 12q: variable expression in two siblings

Genet Couns. 2003;14(2):155-64.


Clinical and cytogenetical findings are reported and discussed on two siblings with discordant phenotypes despite having both a terminal 11q deletion and a distal 12q duplication resulting from an unbalanced segregation of a balanced translocation t(11:12)(q23:q24.1) mat. The oldest child, a girl, is the index patient. Her clinical features include intrauterine and postnatal growth retardation, fetal distress, mild hypotonia, early feeding difficulties, moderate developmental delay, especially in language acquisition, a velopharyngeal insufficiency with repeated otorhinopharyngeal infections, facial dysmorphism, heart ventricular septal defect, and abnormal hyperactive behaviour with sometimes autistic tendencies. The facial dysmorphic features notably consist of microcephaly, hypertelorism, large palpebral fissures, large eyes with alternant divergent strabismus, long eyelashes, a long and broad nasal bridge, a short "crested" nose with salient tip, a fishmouth with large spaces between teeth and flat palate, retrognathism, large ears and multiple dimples. The second affected child is a boy showing low birthweight, moderate developmental retardation with mainly no active language at 32 months, behaviour abnormalities with an autistic tendency, and no major physical anomalies apart from a slight facial hypotonia with often open mouth, dimples on the shoulders and right cryptorchidism. The authors stress the variable clinical expression of the chromosomal imbalance in this family resulting in low birthweight, developmental delay, abnormal behaviour, but different degrees of physical features and dysmorphism. The possible contribution of each of the two aneusomies to the phenotype is discussed.

Publication types

  • Case Reports

MeSH terms

  • Child
  • Child, Preschool
  • Chromosome Deletion*
  • Chromosomes, Human, Pair 11 / genetics*
  • Chromosomes, Human, Pair 12 / genetics*
  • Female
  • Gene Duplication
  • Humans
  • Intellectual Disability / diagnosis
  • Karyotyping
  • Male
  • Severity of Illness Index
  • Siblings*
  • Trisomy / genetics*