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Genetics Library / Genes / FHL1

GENE REFERENCE / HGNC:3702

FHL1

four and a half LIM domains 1

protein-coding geneXq26.3Gene information

What does this gene do?

The FHL1 gene provides instructions for making three versions (isoforms) of a protein that plays an important role in muscles used for movement (skeletal muscles) and in the heart (cardiac muscle). The full-length isoform is known as FHL1A, or sometimes just FHL1. The other two isoforms, which are shorter, are called FHL1B and FHL1C.

FHL1A is the best-studied of the three FHL1 isoforms. Studies suggest that interactions between FHL1A and other proteins play a critical role in the assembly of sarcomeres, which are structures within muscle cells that are necessary for muscle tensing (contraction). These interactions also appear to be involved in chemical signaling within muscle cells, maintaining the structure of these cells, and influencing muscle growth and size.

Less is known about the FHL1B and FHL1C isoforms. FHL1B moves in and out of the nucleus and is also part of the nuclear envelope, which is a structure that surrounds the nucleus in cells. The protein's function in this structure is unknown. FHL1B and FHL1C are suspected to play roles in the normal structure and function of skeletal and cardiac muscles.

Source: MedlinePlus, National Library of Medicine. Source publication: 2023-04-11. Source review: 2017-05.

Related condition topics

MedlinePlus mentions this gene in the condition pages below. These links alone do not show that the gene causes a condition.

ClinGen reviews

We found no matching ClinGen review in the data used here. This does not rule out a link between the gene and a condition.

ClinVar records

These numbers show what has been submitted to ClinVar. They cannot tell you how likely you are to have a condition.

Submitted alleles
878
Submissions for variants in or overlapping this gene
1,411
Submissions explicitly reporting this gene
1,199
Alleles reported pathogenic / likely pathogenic
109
VariationIDs with uncertain significance
277
VariationIDs with conflicting classifications
32

The rows count different things: alleles, submissions or VariationIDs. Their categories can overlap, so do not add them together. Pathogenic/likely pathogenic counts exclude structural variants that merely overlap a gene. A dash in the source means “not reported,” not zero.

NCBI produces the gene-summary file each week using counts recorded at the start of the month. The numbers may differ from those on the live ClinVar website. Read the field definitions ↗

View this gene in ClinVar ↗

YOUR DNA FILE

Can your DNA file tell you about FHL1?

From a DNA test kit (such as 23andMe, AncestryDNA or MyHeritage). These kits check a fixed list of about 600,000 to 700,000 positions across your whole genome. ClinVar lists 109 alleles in FHL1 reported as pathogenic or likely pathogenic. A kit checks only some of these positions, and often none of them.

From whole genome sequencing (a VCF file). Sequencing reads most of your genome. Your file lists the places where your DNA differs from the reference genome. Some regions are hard to sequence, including parts of some genes that have near-identical copies elsewhere, and a VCF file does not record which positions were read well.

If a variant is not in your file, that does not mean you don’t have it.

What BioDecode checks

BioDecode compares every variant in your file with ClinVar, on your own computer. For each match, it shows the ClinVar classification, the review status and the condition it was reported for. Your file is not uploaded.

A ClinVar classification applies to one particular variant and the condition it was reported for. It does not tell you about other variants in FHL1.

BioDecode cannot fill gaps in your test, diagnose a condition or replace clinical testing.

Sources and dates

The source information on this page last changed on 2026-10-10.

HGNC Source details

Open source record ↗

Source release: Fri, 09 Oct 2026 13:40:45 GMT
Source record updated: 2023-01-20

SHA-256: e4cd9c6d7120051b80e5e61d2aeb98bd6a541ddd21f428a6eab922c11242e053

MedlinePlus Source details

Open source record ↗

Source release: Sat, 10 Oct 2026 05:16:07 GMT
Source publication: 2023-04-11
Source review: 2017-05

SHA-256: fdc8bd614310c12718379cef6569962e5d0e791cecabcc355b53a72816ac263a

ClinVar Source details

Open source record ↗

Source release: Sun, 04 Oct 2026 13:15:29 GMT

SHA-256: 126d9e5bded1d43c0380ac6684c86f9aab056d2ff2be93d743e408ed917ae558

About the library sources · Latest validated release · Record 29b36e3f07ab