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PubMed This is a summary of 15 peer-reviewed journal articles Updated
Neurology

The Biology and Genetics of Cobblestone Lissencephaly

At a Glance

Cobblestone lissencephaly is caused by genetic mutations that disrupt a cellular process called glycosylation. This prevents a protein called alpha-dystroglycan from holding brain cells in place during fetal development, causing them to migrate too far and form a lumpy brain surface.

When you first hear terms like “O-glycosylation” or “alpha-dystroglycan,” it can feel like you are learning a foreign language. However, these complex biological processes are simply the body’s instructions for building a stable and organized brain. Understanding how these “building blocks” work can help you visualize why your child’s brain developed differently.

The “Velcro” of the Brain: Alpha-Dystroglycan

Imagine the developing brain as a construction site where billions of nerve cells (neurons) are being moved into their correct positions. To stay in the right place, these cells need a way to “stick” to their surroundings.

The protein alpha-dystroglycan (encoded by the DAG1 gene) acts like a molecular anchor or a piece of high-strength Velcro [1][2]. It sits on the surface of brain and muscle cells, reaching out to grab onto a thin, protective mesh called the pial basement membrane [3][4]. This membrane acts as a boundary—a “stop sign” that tells neurons they have reached the edge of the brain [5].

Glycosylation: Adding the “Sticky” Coating

For this protein “Velcro” to work, it needs a special coating. This process is called glycosylation [6].

Think of glycosylation as adding long, sticky chains of sugar molecules to the protein. Without these sugar chains, the protein is “bald” and cannot grip onto anything [6][5]. When a child has an alpha-dystroglycanopathy, their body has trouble “sugar-coating” the protein correctly [7]. Because the protein isn’t sticky enough, it cannot hold onto the protective pial basement membrane [5][8].

When the Boundary Breaks

During fetal development, if the “Velcro” isn’t working, the pial basement membrane becomes weak and develops small holes or breaches [5][9].

As neurons migrate outward to form the brain’s surface, they don’t see a “stop sign.” Instead, they spill through these holes in the membrane and wander out into the fluid-filled space around the brain [10][11]. This “overmigration” is what creates the lumpy, uneven surface known as cobblestone lissencephaly [10][12].

The Genetic Instruction Manual

The process of adding sugars to proteins is complex and requires several different “workers” (enzymes) to finish the job. Mutations in the genes that provide instructions for these workers are what lead to the diagnosis. Key genes involved include:

  • POMT1 and POMT2: These genes start the process by adding the very first sugar molecules [13].
  • FKTN (Fukutin) and FKRP: These genes add a specific type of sugar (ribitol-phosphate) that is essential for the protein to be “sticky” enough to bind to the brain’s boundary [14][15].
  • DAG1: This gene provides the blueprint for the actual dystroglycan protein itself [1].

Because these same proteins and sugars are also needed to keep muscle cells and eye structures stable, a mutation in any of these genes can affect the brain, muscles, and eyes simultaneously [10][5]. This biological reality leads to the different clinical syndromes discussed on The Spectrum: WWS, MEB, and FCMD page.

Common questions in this guide

What causes the brain to look lumpy in cobblestone lissencephaly?
During fetal development, genetic mutations prevent a key protein called alpha-dystroglycan from working properly. This weakens the protective boundary of the brain, causing developing brain cells to migrate too far outward and create a bumpy or cobblestone-like surface.
How do gene mutations like POMT1 or DAG1 affect my child's development?
These genes provide the instructions for building and coating a protein that helps brain cells stick to their proper places. When these genes have mutations, the cells cannot anchor correctly, which alters the development of the brain.
Why does cobblestone lissencephaly also affect the muscles and eyes?
The same proteins and sugars needed to properly organize the brain are also essential for keeping muscle cells and eye structures stable. A mutation in one of these genes can therefore impact the brain, muscles, and eyes simultaneously.
What does glycosylation mean in my child's diagnosis?
Glycosylation is the process of adding protective sugar chains to proteins so they can function correctly. In cobblestone lissencephaly, the body has trouble adding these sugars, leaving the proteins unable to grip and support developing brain cells.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.Which specific gene (e.g., POMT1, FKTN, FKRP, or DAG1) has a mutation in my child's case?
  2. 2.Based on the specific gene involved, how likely is it that my child will have severe muscle or eye involvement in addition to the brain findings?
  3. 3.Does the specific type of 'hypoglycosylation' seen in my child suggest a more mild or more severe form of the condition?

Questions For You

Tap a prompt to share your answer — we'll use it plus this page's context to start a tailored conversation.

References

References (15)
  1. 1

    NAD+ improves neuromuscular development in a zebrafish model of FKRP-associated dystroglycanopathy.

    Bailey EC, Alrowaished SS, Kilroy EA, et al.

    Skeletal muscle 2019; (9(1)):21 doi:10.1186/s13395-019-0206-1.

    PMID: 31391079
  2. 2

    Inhibitory machinery for the functional dystroglycan glycosylation.

    Kondo Y, Okajima T

    Journal of biochemistry 2023; (173(5)):333-335 doi:10.1093/jb/mvad003.

    PMID: 36760122
  3. 3

    Restoration of the defect in radial glial fiber migration and cortical plate organization in a brain organoid model of Fukuyama muscular dystrophy.

    Taniguchi-Ikeda M, Koyanagi-Aoi M, Maruyama T, et al.

    iScience 2021; (24(10)):103140 doi:10.1016/j.isci.2021.103140.

    PMID: 34632335
  4. 4

    Congenital mirror movements in a patient with alpha-dystroglycanopathy due to a novel POMK mutation.

    Ardicli D, Gocmen R, Talim B, et al.

    Neuromuscular disorders : NMD 2017; (27(3)):239-242 doi:10.1016/j.nmd.2016.12.008.

    PMID: 28109637
  5. 5

    Biallelic Mutations in TMTC3, Encoding a Transmembrane and TPR-Containing Protein, Lead to Cobblestone Lissencephaly.

    Jerber J, Zaki MS, Al-Aama JY, et al.

    American journal of human genetics 2016; (99(5)):1181-1189 doi:10.1016/j.ajhg.2016.09.007.

    PMID: 27773428
  6. 6

    Inhibitory CCK+ basket synapse defects in mouse models of dystroglycanopathy.

    Jahncke JN, Miller DS, Krush M, et al.

    eLife 2024; (12()).

    PMID: 38179984
  7. 7

    Malformations of Core M3 on α-Dystroglycan Are the Leading Cause of Dystroglycanopathies.

    Sharaf-Eldin W

    Journal of molecular neuroscience : MN 2025; (75(1)):28 doi:10.1007/s12031-025-02320-z.

    PMID: 39998573
  8. 8

    Dystroglycanopathies: About Numerous Genes Involved in Glycosylation of One Single Glycoprotein.

    Bouchet-Séraphin C, Vuillaumier-Barrot S, Seta N

    Journal of neuromuscular diseases 2015; (2(1)):27-38.

    PMID: 28198708
  9. 9

    A new patient-derived iPSC model for dystroglycanopathies validates a compound that increases glycosylation of α-dystroglycan.

    Kim J, Lana B, Torelli S, et al.

    EMBO reports 2019; (20(11)):e47967 doi:10.15252/embr.201947967.

    PMID: 31566294
  10. 10

    Cobblestone lissencephaly (Type II), clinical, and neuroimaging: A case report and literature review.

    Sharma PK, Jerosha S, Subramonian SG, et al.

    Radiology case reports 2024; (19(11)):4794-4803 doi:10.1016/j.radcr.2024.07.043.

    PMID: 39228958
  11. 11

    Ectopic clustering of Cajal-Retzius and subplate cells is an initial pathological feature in Pomgnt2-knockout mice, a model of dystroglycanopathy.

    Nakagawa N, Yagi H, Kato K, et al.

    Scientific reports 2015; (5()):11163 doi:10.1038/srep11163.

    PMID: 26060116
  12. 12

    Targeted deletion of RIC8A in mouse neural precursor cells interferes with the development of the brain, eyes, and muscles.

    Kask K, Tikker L, Ruisu K, et al.

    Developmental neurobiology 2018; (78(4)):374-390 doi:10.1002/dneu.22578.

    PMID: 29380551
  13. 13

    Fetal Presentation of Walker-Warburg Syndrome with Compound Heterozygous POMT2 Missense Mutations.

    Zago S, Silvestri E, Arcangeli T, et al.

    Fetal and pediatric pathology 2023; (42(2)):334-341 doi:10.1080/15513815.2022.2116620.

    PMID: 36048137
  14. 14

    ISPD produces CDP-ribitol used by FKTN and FKRP to transfer ribitol phosphate onto α-dystroglycan.

    Gerin I, Ury B, Breloy I, et al.

    Nature communications 2016; (7()):11534 doi:10.1038/ncomms11534.

    PMID: 27194101
  15. 15

    Muscular Dystrophy with Ribitol-Phosphate Deficiency: A Novel Post-Translational Mechanism in Dystroglycanopathy.

    Kanagawa M, Toda T

    Journal of neuromuscular diseases 2017; (4(4)):259-267 doi:10.3233/JND-170255.

    PMID: 29081423

This page provides educational information about the underlying biology of cobblestone lissencephaly. Always consult a pediatric neurologist or genetic counselor to understand your child's specific genetic test results.

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