Harlequin Type Ichthyosis Congenita - Diagnostic Tests

Diagnostic Tests

Immunohistochemistry on skin sections: loss/reduction of ABCA12 expression in the granular layer of the epidermis.

Electron microscopy in HI patients reveals absent or abnormal lamellar granules and lack of intercellular lamellae.

Mutations analysis : Direct sequencing analysis of the ABCA12 gene (from EDTA blood).

During pregnancy, three-dimensional ultrasound enables a greatly improved analysis of the facial morphology.

Diagnostic Tools

This section offers to professional users instruments helpful to establish the disease diagnosis. Specific entries include:

  1. model questionnaires, protocols, or checklists, which may guide clinicians and laboratory personnel in the diagnostic procedure of specific disease groups/subgroups;
  2. a list of cell biology/biochemical tools used for laboratory diagnosis of specific diseases or group of diseases;
  3. a list of molecular genetics tools, including mutational screening procedures, oligonucleotide primer sequences, PCR amplification conditions, and other details for selected diseases. In this section, you also find the link for the gene-specific page of the Weizmann Institute of Science GeneCards website ( which is an integrated database including information on disease relationships, SNPs, gene expression, gene function and more.
  4. a mutation database with a GENESKIN updated list of the mutations identified in the genes responsible for selected diseases. A link with the gene-specific page at the Human Gene Mutation Database maintained at the University of Wales in Cardiff ( and other databases, such as the collagen database in Leicester (, is also available.

Model Questionnaire

Here you will find the downloadable version of the ichthyosis congenita patient form. This document is currently used to collect patient details before sending the biological sample to the diagnostic laboratory, in order to ease cellular and/or molecular investigations.

Ichthyosis patient form

Molecular Genetic Tools

Causative genes

ABCA12 Genecards Logo

Mutation Database

Causative genes