Features of KAT6B-related disorders in a patient with 10q22.1q22.3 deletion

Ophthalmic Genet. 2017 Jul-Aug;38(4):383-386. doi: 10.1080/13816810.2016.1227452. Epub 2016 Nov 23.


Background: Blepharophimosis is a fixed reduction in the vertical distance between the upper and lower eyelids with short palpebral fissures. It is a rare facial malformation and is considered an important diagnostic feature in dysmorphic analysis. It is likely that many patients with blepharophimosis-mental retardation syndrome have submicroscopic chromosomal rearrangements, and the use of molecular karyotyping can narrow the known blepharophimosis-mental retardation-critical regions or clarify the effect of the haploinsufficiency of the involved genes on the phenotype.

Materials and methods: A female patient presented with bilateral blepharophimosis, ptosis, epicanthus inversus, telecanthus, low-set and small ears, other minor anomalies, hypotonia and psychomotor developmental delay. Metabolic investigations and array CGH analysis were performed. The results of molecular karyotyping were confirmed by real-time PCR analysis.

Results: Molecular karyotyping revealed a 5.2 Mb deletion in the 10q22.1q22.3 region. Real-time PCR analysis of the proband and her parents confirmed the deletion in the proband and revealed its de novo origin.

Conclusions: With ptosis, hypotonia, and developmental delay as the main diagnostic features of our patient, the effect of histone acetyltransferase-encoding KAT6B gene haploinsufficiency was suspected to have a significant role in determining the phenotype. Detailed clinical characterization of the patient provided additional information on the clinical manifestation of the 10q22 deletion.

Keywords: 10q22 deletion; KAT6B gene; blepharophimosis; intellectual disability; ptosis.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blepharophimosis / diagnosis*
  • Blepharophimosis / genetics*
  • Child, Preschool
  • Chromosome Deletion*
  • Chromosomes, Human, Pair 10 / genetics*
  • Developmental Disabilities / diagnosis
  • Developmental Disabilities / genetics
  • Female
  • Histone Acetyltransferases / genetics*
  • Humans
  • Intellectual Disability / diagnosis
  • Intellectual Disability / genetics
  • Karyotyping
  • Real-Time Polymerase Chain Reaction
  • Skin Abnormalities / diagnosis*
  • Skin Abnormalities / genetics*
  • Urogenital Abnormalities / diagnosis*
  • Urogenital Abnormalities / genetics*


  • Histone Acetyltransferases
  • KAT6B protein, human

Supplementary concepts

  • Blepharophimosis, Ptosis, and Epicanthus Inversus