National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Caudal regression sequence


Other Names:
Caudal dysplasia; Sacral agenesis syndrome; Sacral regression syndrome; Caudal dysplasia; Sacral agenesis syndrome; Sacral regression syndrome; Sacral agenesis; Sacral defect with anterior meningocele; Caudal regression syndrome See More
Categories:
Caudal regression syndrome is a disorder that impairs the development of the lower (caudal) half of the body. It may affect the lower back (including the spinal cord), limbs, genitourinary tract, and the gastrointestinal tract. The specific features and severity of the disorder vary among affected people. Caudal regression syndrome may have different causes in different people, and is likely caused by a combination of genetic and environmental factors. Maternal diabetes is a major risk factor for the disorder.[1] Most cases are sporadic or are associated with maternal diabetes. Management is supportive and may include surgery. The prognosis is poor; some newborns with severe cases do not survive the neonatal period. Those that survive infancy usually have normal cognitive function.[2]
Last updated: 9/9/2015
The signs and symptoms of caudal regression syndrome vary depending on the severity of the condition. Affected areas of the body may include the lower back, limbs, the genitourinary tract, and the gastrointestinal tract.

The bones of the lower spine are often abnormally shaped or missing, and the corresponding sections of the spinal cord are also abnormal or missing. Affected people can have scoliosis or other abnormalities of the spine. Spinal abnormalities may affect the chest, which can lead to breathing problems.

Some affected people have small hip bones with a limited range of motion. The buttocks may be flat and dimpled. The leg bones are often underdeveloped. In some people, the legs are bent with the knees pointing outward and the feet tucked underneath the hips. Other features affecting the limbs may include clubfeet, calcaneovalgus, and/or decreased sensation in the lower limbs.

Abnormalities of the genitourinary tract are extremely varied. There may be malformations of the kidneys or absence of a kidney, or kidneys that are fused together (horseshoe kidney). Kidney abnormalities can lead to urinary tract infections and progressive kidney failure. There may also be abnormalities of the bladder, or damage to the nerves that control bladder function. Affected males may have hypospadia (the urethra opening on the underside of the penis) or undescended testes. Affected females may have an abnormal connection between the rectum and vagina. In severe cases, an affected person may have no genitalia (genital agenesis).

Gastrointestinal features may include malrotation of the large intestine, an obstruction of the anal opening, and/or inguinal hernias. Constipation and loss of bladder or bowel control are common.[1]
Last updated: 9/9/2015

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Showing of 41 |
Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Abnormal vertebral segmentation and fusion 0005640
Abnormality of the wing of the ilium 0011867
Aplasia/Hypoplasia of the sacrum
Absent/small sacrum
Absent/underdeveloped sacrum
[ more ] 		0008517
Bowel incontinence
Loss of bowel control
0002607
Decreased muscle mass 0003199
Hypoplastic vertebral bodies
Underdeveloped back bones
0008479
Impulsivity
Impulsive
0100710
Maternal diabetes
gestational diabetes
0009800
30%-79% of people have these symptoms
Abnormality of cardiovascular system morphology 0030680
Anal atresia
Absent anus
0002023
Ectopic kidney
Abnormal kidney location
Displaced kidney
[ more ] 		0000086
Joint stiffness
Stiff joint
Stiff joints
[ more ] 		0001387
Reduced tendon reflexes 0001315
Renal agenesis
Absent kidney
Missing kidney
[ more ] 		0000104
Scoliosis 0002650
Talipes equinovarus
Club feet
Club foot
Clubfeet
Clubfoot
[ more ] 		0001762
Ureteral duplication
Double ureter
0000073
Vesicoureteral reflux 0000076
5%-29% of people have these symptoms
Ambiguous genitalia
Ambiguous external genitalia
Ambiguous external genitalia at birth
Intersex genitalia
[ more ] 		0000062
Arnold-Chiari malformation 0002308
Arrhinencephaly 0002139
Cryptorchidism
Undescended testes
Undescended testis
[ more ] 		0000028
Hypertension 0000822
Missing ribs
Absent ribs
Decreased rib number
[ more ] 		0000921
Oral cleft
Cleft of the mouth
0000202
Pulmonary hypoplasia
Small lung
Underdeveloped lung
[ more ] 		0002089
Renal insufficiency
Renal failure
Renal failure in adulthood
[ more ] 		0000083
Percent of people who have these symptoms is not available through HPO
Absence of the sacrum 0010305
Anterior sacral meningocele 0007293
Autosomal dominant inheritance 0000006
Back pain 0003418
Constipation 0002019
Dermoid cyst 0025247
Headache
Headaches
0002315
Hemisacrum 0009790
Meningitis 0001287
Meningocele 0002435
Neurogenic bladder
Lack of bladder control due to nervous system injury
0000011
Rectal abscess 0005224
Sacral lipoma 0012033
Urinary retention 0000016
Showing of 41 |
Last updated: 7/1/2020
Caudal regression syndrome (CRS) may have different causes in different people. In many cases, the cause is unclear.[3][1] It is thought to be a multifactorial disorder, which means that genetic and environmental factors likely interact to cause CRS.[1]

Diabetes in a pregnant woman (maternal diabetes) is a known risk factor for CRS.[1] Increased blood sugar levels and other associated metabolic problems may harm fetal development, increasing the chance to develop CRS. The risk is further increased if the mother's diabetes is poorly managed.[1]

Some researchers believe CRS may be caused by a disruption of mesoderm development in the fetus, which impairs normal formation of the skeleton, gastrointestinal system, and genitourinary system.[1] Others have suggested it may result from the presence of an abnormal artery in the abdomen, which may divert blood flow from the lower body areas of the developing fetus. It is unclear whether abnormal mesoderm development causes reduced blood flow, or whether reduced blood flow causes abnormal mesoderm development. Many scientists think that the cause of CRS is a combination of abnormal mesoderm development and decreased blood flow to the caudal (lower) areas of the developing fetus.[1]
Last updated: 9/10/2015

Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. The following resources provide information relating to diagnosis and testing for this condition. If you have questions about getting a diagnosis, you should contact a healthcare professional.

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.
The long-term outlook (prognosis) for people with caudal regression syndrome depends on the specific features and severity of the condition in each affected person.

Very severely affected newborns may not survive due to cardiac (heart), renal, and/or respiratory complications.[2] In others, the vital systems may be unaffected or minimally affected. Those that survive typically have normal intelligence, with neuromuscular deficits of the lower limbs and sphincters (muscles that control the passage of urine and bowel movements). Secondary neurogenic bladder, leading to progressive renal damage and deterioration of renal function, remains a concern. Therefore, extensive and long-term follow-up of urologic issues is needed.[4]
Last updated: 9/9/2015

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

Related diseases are conditions that have similar signs and symptoms. A health care provider may consider these conditions in the table below when making a diagnosis. Please note that the table may not include all the possible conditions related to this disease.

Conditions with similar signs and symptoms from Orphanet
The main differential diagnosis is sirenomelia (see this term). CRS has also been associated with the VACTERL syndrome (see this term). The Currarino syndrome (see this term) is a form of caudal regression syndrome characterized by the classic triad of presacral mass, sacral bone defect and anorectal malformation in which an autosomal dominant inheritance has been described with mutation or deletion of the HLXB9 gene.
Visit the Orphanet disease page for more information.

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

Living with a genetic or rare disease can impact the daily lives of patients and families. These resources can help families navigate various aspects of living with a rare disease.

Financial Resources

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

  • Genetics Home Reference (GHR) contains information on Caudal regression sequence. This website is maintained by the National Library of Medicine.
  • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.

In-Depth Information

  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Caudal regression sequence. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know. Submit a new question

  • I have a 1 year old granddaughter with caudal regression syndrome. She is recently having blue feet - poor circulation we presume. Is this common for those with this syndrome? It comes and goes throughout the day and doesn't seem to affect her at all. See answer

  • In a non-diabetic mother, what is the most common cause of this condition in a baby? Is there any evidence it can be caused by exposure to medication such as ciproxin? See answer

  • What is caudal regression syndrome? What kind of therapies can we get for a child with this condition? See answer


  1. Caudal regression syndrome. Genetics Home Reference. August, 2015; http://ghr.nlm.nih.gov/condition/caudal-regression-syndrome.
  2. Sylvie Odent. Caudal regression sequence. Orphanet. April, 2010; http://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=en&Expert=3027.
  3. Boulas MM. Recognition of caudal regression syndrome. Adv Neonatal Care. April 2009; 9(2):61-69.
  4. Singh SK, Singh RD, Sharma A. Caudal regression syndrome--case report and review of literature. Pediatr Surg Int. July, 2005; 21(7):578-581.