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PubMed This is a summary of 14 peer-reviewed journal articles Updated
Medical Genetics

Physical and Developmental Features

At a Glance

Ring Chromosome 13 Syndrome causes a wide spectrum of physical and developmental differences due to missing genetic material. Symptoms often include delayed growth, microcephaly, structural brain and heart differences, and intellectual disabilities, varying based on the specific genes affected.

Every child with Ring Chromosome 13 Syndrome is a unique individual. Because the amount of genetic material lost varies from child to child, the symptoms and developmental path also vary widely. This variability is often due to haploinsufficiency—a medical term meaning one copy of a gene is missing, and the remaining copy doesn’t provide enough “instructions” for the body to develop typically [1][2].

Please remember that the conditions listed below represent the full spectrum of possibilities. Very few people have all of these features, and your child’s specific genetic report will help narrow down which risks are most relevant to them.

Growth and Physical Development

Many children with this syndrome begin their journey with intrauterine growth restriction (IUGR), meaning they grew more slowly than expected during pregnancy [3][4]. After birth, growth may continue to be slower, and children may remain smaller than their peers.

Brain and Head (Neurological Features)

The brain is highly sensitive to the genetic “instructions” on chromosome 13. Common findings include:

  • Microcephaly: A smaller-than-average head size, often linked to genes like ARHGEF7 and DIAPH3 [2].
  • Midline Malformations: If the 13q32.3 region is missing, the brain’s midline may not form correctly [5]. This can result in holoprosencephaly (the brain doesn’t divide into two hemispheres) or Dandy-Walker malformation (a difference in the development of the cerebellum, which controls balance) [5][6]. The loss of the ZIC2 gene is a primary driver for these structural brain differences [5].
  • Seizures: Because of the structural differences in the brain, some children are at risk for developing seizures or epilepsy, which are typically managed by a pediatric neurologist [2].

Heart and Internal Organs

Structural differences in the heart and other organs occur in some children, particularly when the 13q33-q34 region is involved [7][8].

  • Congenital Heart Defects (CHD): These can range from simple “holes in the heart” to more complex structures. The gene EFNB2 is often implicated in these differences [9][2].
  • Urogenital and Anorectal Anomalies: Some children may have differences in how their kidneys, bladder, or digestive tract formed [7][8]. This can include things like renal hypoplasia (smaller kidneys) [7].
  • Retinoblastoma Risk: If the RB1 gene (at 13q14.2) is lost, there is a significantly increased risk for a rare eye cancer called retinoblastoma, requiring frequent specialist screenings [10][11].

Intellectual and Developmental Spectrum

Developmental delay is common, but the degree varies from mild to profound [12][13].

  • Milestones: Children may be slower to reach milestones like sitting, walking, or talking [13].
  • Cognitive Ability: While many children have intellectual disabilities, some cases involving specific small deletions (like the CHAMP1 gene) may result in milder challenges [14].
  • Communication: Speech delays are frequently reported, and many families find that early intervention with speech, physical, and occupational therapy is highly beneficial [13].

Common questions in this guide

How does Ring Chromosome 13 Syndrome affect my child's physical development?
Many children experience slow growth during pregnancy and remain smaller than average after birth. The degree of developmental delay varies widely based on exactly how much genetic material is missing from the chromosome.
What are the common brain malformations in Ring Chromosome 13?
Children may have a smaller head size, known as microcephaly. If specific genes are missing, they may also experience midline brain differences like holoprosencephaly or Dandy-Walker malformation, which can increase the risk of seizures.
Does my child need special cancer screenings if they have Ring Chromosome 13?
Yes, if the RB1 gene is missing from your child's chromosome 13, they have a significantly higher risk of developing a rare eye cancer called retinoblastoma. Frequent specialist screenings are required to monitor their eye health closely.
Will my child with Ring 13 syndrome experience heart or kidney problems?
Some children with specific deletions on chromosome 13 develop congenital heart defects or urogenital differences like smaller kidneys. Your doctor will likely recommend regular heart and kidney screenings to check for these potential structural issues.
What treatments are available for developmental delays in Ring Chromosome 13 Syndrome?
While there is no cure for the chromosomal change itself, early intervention is highly beneficial. Speech, physical, and occupational therapy can help children reach their maximum developmental potential and improve their communication skills.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.Based on my child's breakpoints, which specific genes (like ZIC2, EFNB2, or RB1) are missing, and what are the specific risks associated with those losses?
  2. 2.Does my child need a brain MRI to look for malformations like holoprosencephaly or Dandy-Walker, even if they aren't showing symptoms yet?
  3. 3.What is the recommended schedule for heart and kidney screenings based on the current guidelines for 13q deletions?
  4. 4.How does the level of mosaicism in my child's latest test affect our expectations for their developmental progress?
  5. 5.Which specialists (e.g., neurologist, cardiologist, urologist) should be part of our initial care team?

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 (14)
  1. 1

    Two Cases with Ring Chromosome 13 at either End of the Phenotypic Spectrum.

    Çakmaklı S, Çankaya T, Gürsoy S, et al.

    Cytogenetic and genome research 2017; (153(4)):175-180 doi:10.1159/000486775.

    PMID: 29518772
  2. 2

    Deletion of Chromosome 13 due to Different Rearrangements and Impact on Phenotype.

    Bellucco FT, Rodrigues de Oliveira-Júnior H, Santos Guilherme R, et al.

    Molecular syndromology 2019; (10(3)):139-146 doi:10.1159/000497402.

    PMID: 31191202
  3. 3

    Prenatal diagnosis and molecular cytogenetic characterization of mosaicism for r(13), monosomy 13 and idic r(13) by amniocentesis.

    Chen CP, Chen CY, Chern SR, et al.

    Taiwanese journal of obstetrics & gynecology 2020; (59(1)):130-134 doi:10.1016/j.tjog.2019.11.021.

    PMID: 32039781
  4. 4

    Prenatal diagnosis of recurrent mosaic ring chromosome 13 of maternal origin.

    Chen CP, Chen CY, Chern SR, et al.

    Taiwanese journal of obstetrics & gynecology 2021; (60(4)):771-774 doi:10.1016/j.tjog.2021.05.033.

    PMID: 34247823
  5. 5

    Prenatal diagnosis of distal 13q deletion syndrome in a fetus with esophageal atresia: a case report and review of the literature.

    Kotani T, Tsuda H, Ito Y, et al.

    Journal of medical case reports 2022; (16(1)):481 doi:10.1186/s13256-022-03713-z.

    PMID: 36572904
  6. 6

    22.5 MB DELETION OF 13q31.1-q34 ASSOCIATED WITH HPE, DWM, AND HSCR: A CASE REPORT AND REDEFINING THE SMALLEST DELETED REGIONS.

    Alp MY, Çebi AH, Seyhan S, et al.

    Genetic counseling (Geneva, Switzerland) 2016; (27(1)):43-9.

    PMID: 27192891
  7. 7

    Reduced anogenital distance, hematuria and left renal hypoplasia in a patient with 13q33.1-34 deletion: case report and literature review.

    He X, Shen H, Fu H, et al.

    BMC pediatrics 2020; (20(1)):327 doi:10.1186/s12887-020-02205-7.

    PMID: 32616040
  8. 8

    The rare 13q33-q34 microdeletions: eight new patients and review of the literature.

    Sagi-Dain L, Goldberg Y, Peleg A, et al.

    Human genetics 2019; (138(10)):1145-1153 doi:10.1007/s00439-019-02048-y.

    PMID: 31321490
  9. 9

    Chromosome 13q deletion syndrome involving 13q31‑qter: A case report.

    Wang YP, Wang DJ, Niu ZB, Cui WT

    Molecular medicine reports 2017; (15(6)):3658-3664 doi:10.3892/mmr.2017.6425.

    PMID: 28393221
  10. 10

    13q deletion syndrome resulting from balanced chromosomal rearrangement in father: the significance of parental karyotyping.

    Dittner-Moormann S, Reschke M, Biewald E, et al.

    Molecular cytogenetics 2020; (13()):31 doi:10.1186/s13039-020-00500-7.

    PMID: 32760450
  11. 11

    Retinoblastoma management in 13q deletion syndrome patients using super-selective chemotherapies and other cancer-directed interventions.

    Cobbs LV, Francis JH, Dunkel IJ, et al.

    Pediatric blood & cancer 2021; (68(5)):e28845 doi:10.1002/pbc.28845.

    PMID: 33355996
  12. 12

    Molecular and Cytogenetic Characterization of a Fetus with Mosaic Ring Chromosome 13: A Very Rare Case.

    Zhao XR, Han X, Wang YL, Hu WJ

    Chinese medical journal 2017; (130(24)):3007-3008 doi:10.4103/0366-6999.220308.

    PMID: 29237938
  13. 13

    Induced pluripotent stem cell line, IMGTi003-A, derived from skin fibroblasts of an intellectually disabled patient with ring chromosome 13.

    Nikitina TV, Menzorov AG, Kashevarova AA, et al.

    Stem cell research 2018; (33()):260-264 doi:10.1016/j.scr.2018.11.009.

    PMID: 30500678
  14. 14

    Cytogenetic and molecular characterization of a patient having infertility and mild intellectual disability with a very rare unstable ring chromosome 13.

    Kaya M, Suer I, Kalayci T, et al.

    Scottish medical journal 2022; (67(4)):173-177 doi:10.1177/00369330221114426.

    PMID: 35862016

This page provides educational information about the features of Ring Chromosome 13 Syndrome. Always consult a medical geneticist or your child's pediatrician for personalized advice and medical screening.

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