# Genetic syndromes in paediatric alopecia areata: a systematic review

## TL;DR

This review identifies 33 genetic syndromes linked to childhood alopecia areata, helping improve diagnosis and treatment.

## Contribution

A comprehensive catalog of 33 genetic syndromes associated with pediatric alopecia areata is systematically compiled.

## Key findings

- 33 distinct genetic syndromes with pediatric alopecia areata were identified and summarized.
- 67% of the syndromes are fully genetically elucidated, while 12% remain partially or not elucidated.
- Most syndromes (79%) are reported in only one study, highlighting limited data availability.

## Abstract

A wide variation of phenotypes is displayed by individuals with alopecia areata (AA), especially in the paediatric population.

To systematically search published studies to identify paediatric syndromes with AA and their clinical features, and to summarize the current state of their genetic elucidation.

In accordance with the PRISMA guidelines, a systematic search of MEDLINE, Embase, CENTRAL and PubMed databases was performed. All original case reports, case series and observational studies describing AA in children (aged <18 years) with monogenic or chromosomal syndromes were included. Further searches in OMIM and Orphanet, and reviews, clinical guidelines and basic science studies were used to retrieve additional comprehensive information on each syndrome.

After title and abstract screening of 1426 studies, and full-text review of 224 studies, 64 met the inclusion criteria and are summarized in this review. Overall, the search identified 33 genetic syndromes with paediatric AA. Prevalence estimates were available for 79% (n = 26/33) of syndromes, with 45% (n = 15/33) of syndromes presenting in fewer than 1/1 000 000 individuals. Sixty-seven per cent (n = 22/33) of syndromes were fully genetically elucidated; 12% (n = 4/33) were partially elucidated; 9% (n = 3/33) were not genetically elucidated; and 12% (n = 4/33) were syndromes with chromosomal abnormalities. Seventy-nine per cent (n = 26/33) of syndromes were described by only one report, while 21% (n = 7/33) were described in multiple independent reports.

Despite the limited knowledge of these syndromes, this review provides insights into the range of genetic syndromes with paediatric AA and their clinical features, facilitating early prediction, diagnosis and personalized treatments.

There is a wide variation of phenotypes displayed by individuals with alopecia areata (AA), especially in the paediatric population. This review aims to systematically search published studies to identify paediatric syndromes with AA and their clinical features, and to summarize the current state of their genetic elucidation. Overall, this review identifies and summarizes a total of 33 distinct syndromes associated with paediatric AA into a comprehensive catalogue.