Expanding the phenotypic spectrum of ARCN1-related syndrome

Genet Med. 2022 Jun;24(6):1227-1237. doi: 10.1016/j.gim.2022.02.005. Epub 2022 Mar 14.


Purpose: This study aimed to describe the phenotypic and molecular characteristics of ARCN1-related syndrome.

Methods: Patients with ARCN1 variants were identified, and clinician researchers were connected using GeneMatcher and physician referrals. Clinical histories were collected from each patient.

Results: In total, we identified 14 cases of ARCN1-related syndrome, (9 pediatrics, and 5 fetal cases from 3 families). The clinical features these newly identified cases were compared to 6 previously reported cases for a total of 20 cases. Intrauterine growth restriction, micrognathia, and short stature were present in all patients. Other common features included prematurity (11/15, 73.3%), developmental delay (10/14, 71.4%), genitourinary malformations in males (6/8, 75%), and microcephaly (12/15, 80%). Novel features of ARCN1-related syndrome included transient liver dysfunction and specific glycosylation abnormalities during illness, giant cell hepatitis, hepatoblastoma, cataracts, and lethal skeletal manifestations. Developmental delay was seen in 73% of patients, but only 3 patients had intellectual disability, which is less common than previously reported.

Conclusion: ARCN1-related syndrome presents with a wide clinical spectrum ranging from a severe embryonic lethal syndrome to a mild syndrome with intrauterine growth restriction, micrognathia, and short stature without intellectual disability. Patients with ARCN1-related syndrome should be monitored for liver dysfunction during illness, cataracts, and hepatoblastoma. Additional research to further define the phenotypic spectrum and possible genotype-phenotype correlations are required.

Keywords: ARCN1; COPI; Micrognathia.

Publication types

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

MeSH terms

  • Cataract*
  • Child
  • Dwarfism*
  • Female
  • Fetal Growth Retardation / genetics
  • Hepatoblastoma*
  • Humans
  • Intellectual Disability* / genetics
  • Liver Neoplasms*
  • Male
  • Micrognathism*
  • Phenotype
  • Syndrome