On this page
MLYCD
malonyl-CoA decarboxylase
The MLYCD gene provides instructions for producing malonyl-CoA decarboxylase, an enzyme essential for the regulation of fatty acid formation and breakdown within the body. MLYCD plays a vital role in cellular energy production by controlling fatty acid metabolism.
MLYCD is located on the long (q) arm of chromosome 16, at band 16q23.3. Arm ratio per GRCh38 - banding schematic.
Explore chromosome 16 in the library →Available at Jeen Health
Clinical tests that include this
Overview
The MLYCD gene encodes the enzyme malonyl-CoA decarboxylase, which is critical for fatty acid regulation. This enzyme primarily functions in tissues with high energy demands, such as cardiac muscles, but is also present in the brain, skeletal muscles, liver, pancreas, kidneys, and small intestine.
Its main role is to help maintain the balance between the synthesis and degradation of fatty acids, which are vital for energy supply, cell membrane structure, and hormone production.
What the gene does
Malonyl-CoA decarboxylase, produced from the MLYCD gene, is involved in a key step of fatty acid metabolism. The enzyme facilitates the conversion of malonyl-CoA to acetyl-CoA. Malonyl-CoA typically inhibits the breakdown of fatty acids, so by converting it to acetyl-CoA, malonyl-CoA decarboxylase helps to regulate when fatty acids are formed and when they are broken down for energy.
This enzymatic activity is crucial for cellular energy homeostasis. Acetyl-CoA is a necessary building block for new fatty acids, and its production from malonyl-CoA helps ensure that cells have the appropriate balance of fatty acid synthesis and oxidation.
Video: Genetics 101
Chromosome location
The MLYCD gene is situated on chromosome 16 at position 16q23.3. This specific location on the long arm of chromosome 16 helps define its genomic address within the human genome.
Protein structure
The malonyl-CoA decarboxylase protein, encoded by the MLYCD gene, consists of 493 amino acids. It features a distinct Alpha-helical domain located between amino acids 40 and 190, and a Catalytic domain from amino acids 191 to 493. Additionally, a Microbody targeting signal is found at amino acids 491-493, indicating its potential localisation within cellular microbodies.
Key variants
Genetic variations in the MLYCD gene can affect the enzyme's structure or function. Pathogenic variants are alterations that impair the normal activity of malonyl-CoA decarboxylase, leading to metabolic dysfunction. These genetic changes are typically identified through sequencing tests.
Sample of pathogenic variants
10 pathogenic / likely-pathogenic variants from ClinVar, ranked by review status (expert-panel-reviewed first). This is a sample; recurrent founder variants in a specific population may not appear here - see the full ClinVar listing via the link above.
| Variant (HGVS) | Protein change | Classification | Evidence | Associated condition |
|---|---|---|---|---|
c.1005del | p.Lys336fs | Pathogenic/Likely pathogenic | ★★☆☆ | Deficiency of malonyl-CoA decarboxylase |
c.193G>T | p.Glu65Ter | Pathogenic/Likely pathogenic | ★★☆☆ | Deficiency of malonyl-CoA decarboxylase |
c.237_269delinsGTAGA | p.Glu80_Arg90delinsTer | Pathogenic/Likely pathogenic | ★★☆☆ | Deficiency of malonyl-CoA decarboxylase |
c.393_400del | p.Leu133fs | Pathogenic | ★★☆☆ | Deficiency of malonyl-CoA decarboxylase |
c.560C>G | p.Ser187Ter | Pathogenic | ★★☆☆ | Deficiency of malonyl-CoA decarboxylase |
c.953_954del | - | Pathogenic | ★★☆☆ | Deficiency of malonyl-CoA decarboxylase |
GRCh37/hg19 16q23.3(chr16:83883746-83971242)x1 | - | Pathogenic | ★☆☆☆ | not specified |
c.172G>T | p.Glu58Ter | Pathogenic | ★☆☆☆ | not provided |
c.247C>T | p.Gln83Ter | Pathogenic | ★☆☆☆ | Deficiency of malonyl-CoA decarboxylase |
c.570_571dup | p.Ser191fs | Pathogenic | ★☆☆☆ | Deficiency of malonyl-CoA decarboxylase |
Evidence stars indicate ClinVar review status. Individual variant interpretation should always be performed by a qualified clinical laboratory - many variants remain classified as Variants of Uncertain Significance (VUS) pending more research.
Associated conditions
Pathogenic variants within the MLYCD gene are the underlying cause of malonyl-CoA decarboxylase deficiency. This inherited metabolic disorder impairs the body's ability to properly metabolise fatty acids, leading to an inability to convert them into energy. Symptoms of malonyl-CoA decarboxylase deficiency often manifest in infancy or childhood and can include developmental delay and low blood glucose (hypoglycaemia).
No disease links recorded for this gene in our reference set.
UK clinical status
The MLYCD gene is included in several NHS Genomic Medicine Service national panels, indicating its clinical relevance in the UK. It is listed as green in DDG2P, Foetal anomalies (R21), Hyperammonaemia, Intellectual disability, Likely inborn error of metabolism (R98), Paediatric or syndromic cardiomyopathy (R135), and Undiagnosed metabolic disorders, signifying that variants in this gene are considered to have a strong association with these conditions.
Sources: NHS GMS PanelApp · Genomics England PanelApp · NHS National Genomic Test Directory
Frequently asked questions
What is the primary function of the MLYCD gene?
The MLYCD gene provides instructions for the malonyl-CoA decarboxylase enzyme, which regulates the formation and breakdown of fatty acids in the body, essential for energy production and other cellular processes.
What condition is associated with MLYCD gene variants?
Pathogenic variants in the MLYCD gene cause malonyl-CoA decarboxylase deficiency, a metabolic disorder that affects the body's ability to convert fatty acids into energy, leading to symptoms like developmental delay and low blood glucose.
Where is the MLYCD gene located?
The MLYCD gene is located on chromosome 16, specifically at position 16q23.3.
References
- Salomons GS, Jakobs C, Pope LL. Clinical, enzymatic and molecular characterization of nine new patients with malonyl-coenzyme A decarboxylase deficiency. Journal of inherited metabolic disease. 2007. PMID: 17186413
- Wightman PJ, Santer R, Ribes A. MLYCD mutation analysis: evidence for protein mistargeting as a cause of MLYCD deficiency. Human mutation. 2003. PMID: 12955715
- Surendran S, Sacksteder KA, Gould SJ. Malonyl CoA decarboxylase deficiency: C to T transition in intron 2 of the MCD gene. Journal of neuroscience research. 2001. PMID: 11550227