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Resources

References:

1. Consortium For The Application Of Single-Molecule Real-Time Sequencing For The Precision Medicine And Control Of Thalassemia, Group Of Clinical Genetics Medical Genetics Branch Of Chinese Medical Doctor Association, Wu L. Zhonghua Yi Xue Yi Chuan Xue Za Zhi. 2025;42(4):385-396.

2. Liang Q, Gu W, Chen P, et al. A More Universal Approach to Comprehensive Analysis of Thalassemia Alleles (CATSA). J Mol Diagn. 2021;23(9):1195-1204.

3. Huang R, Liu Y, Xu J, et al. Back-to-Back Comparison of Third-Generation Sequencing and Next-Generation Sequencing in Carrier Screening of Thalassemia. Arch Pathol Lab Med. 2024;148(7):797-804.

4. Li S, Hua R, Han X, et al. Targeted long-read sequencing facilitates effective carrier screening for complex monogenic diseases including spinal muscular atrophy, α-/β-thalassemia, 21-hydroxylase deficiency, and fragile-X syndrome. J Transl Med. 2025;23(1):307.

5. Liang Q, He J, Li Q, et al. Evaluating the Clinical Utility of a Long-Read Sequencing-Based Approach in Prenatal Diagnosis of Thalassemia. Clin Chem. 2023;69(3):239-250.

Long-Read Sequencing 

Comprehensive Analysis of Ichthyosis Vulgaris

Genetics of Ichthyosis Vulgaris

Ichthyosis vulgaris is the most common inherited ichthyosis and is typically associated with loss-of-function variants in FLG, the gene encoding filaggrin. It is usually inherited in an autosomal semidominant pattern, with variable expressivity and incomplete penetrance.

Although ichthyosis vulgaris is often diagnosed clinically, genetic testing can support diagnosis in atypical or complex presentations and help distinguish it from other conditions, including atopic dermatitis, eczema, and X-linked ichthyosis. Short-read sequencing may have reduced sensitivity in FLG, particularly within the large, highly repetitive exon 3, where read mapping and variant interpretation can be challenging.This can reduce mapping confidence and limit reliable detection of clinically relevant FLG variants.

Long-Read FLG Sequencing

Our long-read FLG sequencing assay, Comprehensive Analysis of Ichthyosis Vulgaris, is designed to support more reliable analysis, where short-read sequencing may have reduced mapping confidence.

Improve Analysis of the Repetitive Region

Provides enhanced coverage across the key difficult-to-map FLG exon 3 region with long-read

Assist Differential Diagnosis

Supports distinction of FLG-related ichthyosis vulgaris from overlapping dermatologic conditions

Send-out Testing

When considering our send-out sequencing services:

  1. Consultation: Contact our team for the most current test specifications.

  2. Sample Preparation: Check sample types and shipment requirements to ensure high-quality results. Please check your local export regulations and logistics partners.

  3. Submission: Contact Xcelom when placing an order. Include the completed Test Request and Consent Form, along with any required documents.

Sample Requirements

Peripheral Blood: 2 mL in EDTA tube

Dried Blood Spot (DBS): 3 spots, ≥ 8mm diameter each

gDNA: >10 ng/uL and >30 nL

Transport Conditions

2-8℃, arrive within 72 hours

Testing Scope

Detects the FLG variants (P, LP, and selected VUS SNVs/InDels within exon 3) associated with ichthyosis vulgaris

Turnaround Time (TAT)

15 working days

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