Mutations of DNAI1 in primary ciliary dyskinesia: evidence of founder effect in a common mutation

Am J Respir Crit Care Med. 2006 Oct 15;174(8):858-66. doi: 10.1164/rccm.200603-370OC. Epub 2006 Jul 20.

Abstract

Rationale: Primary ciliary dyskinesia (PCD) is a rare, usually autosomal recessive, genetic disorder characterized by ciliary dysfunction, sino-pulmonary disease, and situs inversus. Disease-causing mutations have been reported in DNAI1 and DNAH5 encoding outer dynein arm (ODA) proteins of cilia.

Objectives: We analyzed DNAI1 to identify disease-causing mutations in PCD and to determine if the previously reported IVS1+2_3insT (219+3insT) mutation represents a "founder" or "hot spot" mutation.

Methods: Patients with PCD from 179 unrelated families were studied. Exclusion mapping showed no linkage to DNAI1 for 13 families; the entire coding region was sequenced in a patient from the remaining 166 families. Reverse transcriptase-polymerase chain reaction (RT-PCR) was performed on nasal epithelial RNA in 14 families.

Results: Mutations in DNAI1 including 12 novel mutations were identified in 16 of 179 (9%) families; 14 harbored biallelic mutations. Deep intronic splice mutations were not identified by reverse transcriptase-polymerase chain reaction. The prevalence of mutations in families with defined ODA defect was 13%; no mutations were found in patients without a defined ODA defect. The previously reported IVS1+2_3insT mutation accounted for 57% (17/30) of mutant alleles, and marker analysis indicates a common founder for this mutation. Seven mutations occurred in three exons (13, 16, and 17); taken together with previous reports, these three exons are emerging as mutation clusters harboring 29% (12/42) of mutant alleles.

Conclusions: A total of 10% of patients with PCD are estimated to harbor mutations in DNAI1; most occur as a common founder IVS1+2_3insT or in exons 13, 16, and 17. This information is useful for establishing a clinical molecular genetic test for PCD.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Axonemal Dyneins
  • Child
  • Child, Preschool
  • DNA / genetics*
  • Dyneins / genetics*
  • Exons
  • Female
  • Founder Effect
  • Gene Frequency
  • Genotype
  • Humans
  • Infant
  • Kartagener Syndrome / genetics*
  • Male
  • Mutation*
  • Pedigree
  • Phenotype
  • Polymerase Chain Reaction

Substances

  • DNAI1 protein, human
  • DNA
  • Axonemal Dyneins
  • Dyneins