Novel heterozygous pathogenic variants in CHUK in a patient with AEC-like phenotype, immune deficiencies and 1q21.1 microdeletion syndrome: a case report

BMC Med Genet. 2018 Mar 9;19(1):41. doi: 10.1186/s12881-018-0556-2.

Abstract

Background: Ectodermal dysplasias (ED) are a group of diseases that affects the development or function of the teeth, hair, nails and exocrine and sebaceous glands. One type of ED, ankyloblepharon-ectodermal defects-cleft lip/palate syndrome (AEC or Hay-Wells syndrome), is an autosomal dominant disease characterized by the presence of skin erosions affecting the palms, soles and scalp. Other clinical manifestations include ankyloblepharon filiforme adnatum, cleft lip, cleft palate, craniofacial abnormalities and ectodermal defects such as sparse wiry hair, nail changes, dental changes, and subjective hypohydrosis.

Case presentation: We describe a patient presenting clinical features reminiscent of AEC syndrome in addition to recurrent infections suggestive of immune deficiency. Genetic testing for TP63, IRF6 and RIPK4 was negative. Microarray analysis revealed a 2 MB deletion on chromosome 1 (1q21.1q21.2). Clinical exome sequencing uncovered compound heterozygous variants in CHUK; a maternally-inherited frameshift variant (c.1365del, p.Arg457Aspfs*6) and a de novo missense variant (c.1388C > A, p.Thr463Lys) on the paternal allele.

Conclusions: To our knowledge, this is the fourth family reported with CHUK-deficiency and the second patient with immune abnormalities. This is the first case of CHUK-deficiency with compound heterozygous pathogenic variants, including one variant that arose de novo. In comparison to cases found in the literature, this patient demonstrates a less severe phenotype than previously described.

Keywords: 1q21.1 microdeletion syndrome; AEC; Bartsocas–Papas syndrome; CHUK; Cocoon syndrome.

Publication types

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

MeSH terms

  • Abnormalities, Multiple / genetics*
  • Amino Acid Sequence
  • Child, Preschool
  • Chromosome Deletion
  • Chromosomes, Human, Pair 1 / genetics
  • Cleft Lip / diagnosis
  • Cleft Lip / genetics
  • Cleft Palate / diagnosis
  • Cleft Palate / genetics
  • Ectodermal Dysplasia / diagnosis
  • Ectodermal Dysplasia / genetics
  • Eye Abnormalities / diagnosis
  • Eye Abnormalities / genetics
  • Eyelids / abnormalities
  • Gene Frequency
  • Genetic Testing
  • Genetic Variation
  • Heterozygote
  • Humans
  • I-kappa B Kinase / genetics*
  • Immunoglobulin G / blood
  • Immunologic Deficiency Syndromes / diagnosis*
  • Immunologic Deficiency Syndromes / genetics*
  • Interferon Regulatory Factors / genetics
  • Male
  • Megalencephaly / genetics*
  • Microarray Analysis
  • Mutation, Missense
  • Pedigree
  • Phenotype
  • Protein Serine-Threonine Kinases / genetics
  • Transcription Factors / genetics
  • Tumor Suppressor Proteins / genetics

Substances

  • IRF6 protein, human
  • Immunoglobulin G
  • Interferon Regulatory Factors
  • TP63 protein, human
  • Transcription Factors
  • Tumor Suppressor Proteins
  • RIPK4 protein, human
  • Protein Serine-Threonine Kinases
  • CHUK protein, human
  • I-kappa B Kinase

Supplementary concepts

  • Chromosome 1q21.1 Deletion Syndrome, 1.35-Mb
  • Hay-Wells syndrome