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PubMed This is a summary of 17 peer-reviewed journal articles Updated
Genetics · Multicystic Dysplastic Kidney

Genetics and Renal Dysplasia: Do You Need Testing?

At a Glance

Most children with multicystic dysplastic kidney (MCDK) do not need genetic testing if the condition only affects one kidney. Testing is recommended when there are red flags like issues in the other kidney, birth defects in other organs, or a family history of kidney disease or early diabetes.

For most parents, a diagnosis of Multicystic Dysplastic Kidney (MCDK) is “isolated,” meaning it only affects one kidney and is not part of a larger genetic syndrome [1][2]. In these cases, the risk of a genetic cause is low, and routine genetic testing is often not initially necessary. However, in some children, the kidney issue is a “clue” to an underlying genetic condition that might affect other parts of the body [1][3].

When to Consider Genetic Testing

Doctors generally consider genetic testing and counseling if there are “red flags” that suggest the MCDK is syndromic (part of a syndrome) rather than isolated. These red flags include:

  • Issues with the “Healthy” Kidney: If the other kidney also has cysts, is very small, or has severe reflux (a condition known collectively as CAKUT - Congenital Anomalies of the Kidney and Urinary Tract) [4][5].
  • Extra-Renal Anomalies: Birth defects or health issues in other organs (like the heart, ears, eyes, or genitals) [3][6].
  • Family History: Multiple relatives with kidney cysts, early-onset diabetes, or hearing loss [5][7].

Key Genes and Their “Signature” Signs

If your doctor suspects a genetic cause, they will likely look at a few specific genes known to influence kidney development. Each has a unique “signature” of symptoms:

Gene Syndrome Name Signs Beyond the Kidney
HNF1B RCAD Syndrome Low magnesium, reproductive tract (Mullerian) anomalies, or MODY5 diabetes (which typically presents in adolescence or early adulthood, not in infancy) [8][9][10].
PAX2 Renal-Coloboma Syndrome Abnormalities of the optic nerve in the eye (colobomas), which can affect vision [11][12][13].
GATA3 HDR Syndrome Hypoparathyroidism, deafness (hearing loss), and renal dysplasia [14].
TSHZ3 CAKUT Spectrum Variable presentations, often linked to non-syndromic and syndromic kidney anomalies [3].

Types of Genetic Tests

If testing is recommended, your medical team might use several different tools:

  • Chromosomal Microarray (CMA): This test looks for missing or extra “chunks” of genetic material.
  • Whole Exome Sequencing (WES): This is a more detailed test that “spells out” the DNA of all your genes to look for tiny mutations [15][16].
  • Trio Sequencing: This is a type of WES where the child and both parents are tested at the same time. This helps doctors quickly figure out if a mutation is new in the child (de novo) or inherited from a parent. It is increasingly used as a first-line diagnostic strategy for pediatric kidney disease [15][17].

Why Does It Matter?

Knowing if a child has a specific genetic mutation helps doctors personalize their care. For example, if a child has an HNF1B mutation, the team will know to monitor their magnesium levels and watch for diabetes as they enter adolescence [8][10]. If they have a PAX2 mutation, early and regular eye exams become a priority to protect their vision [11].

For most children, however, a thorough physical exam and a normal ultrasound of the other kidney are enough to provide reassurance that the condition is isolated and does not require extensive genetic testing [1][4].

Common questions in this guide

Does my child need genetic testing for isolated MCDK?
Most children with isolated MCDK, meaning it affects only one kidney and there are no other health issues, do not need genetic testing. A thorough physical exam and normal ultrasound of the other kidney usually provide enough reassurance.
What are the red flags that suggest MCDK might be part of a genetic syndrome?
Doctors may recommend genetic testing if the child's other kidney has cysts or severe reflux, if there are birth defects in other organs like the heart or eyes, or if there is a family history of kidney cysts, early-onset diabetes, or hearing loss.
What does an HNF1B gene mutation mean for my child?
An HNF1B mutation can cause RCAD syndrome. If your child has this genetic mutation, their medical team will know to closely monitor their magnesium levels and watch for signs of diabetes as they reach adolescence.
What types of genetic tests are used for pediatric kidney disease?
Doctors may use a Chromosomal Microarray (CMA) to look for missing or extra chunks of genetic material, or Whole Exome Sequencing (WES) to find tiny DNA mutations. Sometimes, they use Trio Sequencing to test the child and both parents simultaneously.
Why is it important to know the specific genetic cause of renal dysplasia?
Identifying a specific genetic mutation helps doctors personalize your child's care. It allows the medical team to proactively monitor for specific health issues associated with that gene, such as arranging early eye exams if vision issues are a risk.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.Does my child have 'isolated' MCDK, or are there any signs that this could be part of a syndrome?
  2. 2.Given my child's ultrasound findings, do you recommend a chromosomal microarray (CMA) or whole exome sequencing (WES)?
  3. 3.Should we have my child's eyes checked by an ophthalmologist for optic nerve colobomas?
  4. 4.Do we need to check my child's magnesium levels to look for signs of an HNF1B mutation?
  5. 5.Are there any physical features, like ear pits or thumb issues, that you see that might suggest a specific genetic syndrome?

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 (17)
  1. 1

    Multicystic dysplastic kidneys (MCDK) during prenatal life and postnatal outcome.

    Reinhardt CJM, Henrich W, Verlohren S, et al.

    Archives of gynecology and obstetrics 2025; (312(6)):2131-2146 doi:10.1007/s00404-025-08197-y.

    PMID: 41107504
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    Clinical outcome of children with prenatally diagnosed isolated unilateral multicystic dysplastic kidney.

    Huettinger M, Bogner G, Fischer T, et al.

    European journal of obstetrics, gynecology, and reproductive biology 2025; (312()):114112 doi:10.1016/j.ejogrb.2025.114112.

    PMID: 40517513
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    Heterozygous variants in the teashirt zinc finger homeobox 3 (TSHZ3) gene in human congenital anomalies of the kidney and urinary tract.

    Kesdiren E, Martens H, Brand F, et al.

    European journal of human genetics : EJHG 2025; (33(1)):44-55 doi:10.1038/s41431-024-01710-y.

    PMID: 39420202
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    Unilateral multicystic dysplastic kidney disease associated with ipsilateral ureteric bud remnant and contralateral duplex collecting system.

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    Radiology case reports 2023; (18(6)):2289-2292 doi:10.1016/j.radcr.2023.03.048.

    PMID: 37153488
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    New PAX2 Mutation Associated with Polycystic Kidney Disease: A Case Report.

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    Clinical medicine insights. Pediatrics 2021; (15()):1179556521992354 doi:10.1177/1179556521992354.

    PMID: 33746522
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    A case of right hypodysplastic kidney and ectopic ureter associated with bicornuate uterus in a prepubertal girl.

    Nakamura M, Kanda S, Kajiho Y, et al.

    CEN case reports 2023; (12(1)):122-129 doi:10.1007/s13730-022-00730-1.

    PMID: 36056295
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    New insights into the role of HNF-1β in kidney (patho)physiology.

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    Pediatric nephrology (Berlin, Germany) 2019; (34(8)):1325-1335 doi:10.1007/s00467-018-3990-7.

    PMID: 29961928
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    Hnf1b haploinsufficiency differentially affects developmental target genes in a new renal cysts and diabetes mouse model.

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    EARLY ONSET OF MODY5 DUE TO HAPLOINSUFFICIENCY OF HNF1B.

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    Importance of Genetic Diagnostics in Adult-Onset Focal Segmental Glomerulosclerosis.

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    PAX2 Gene Mutation in Pediatric Renal Disorders-A Narrative Review.

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    International journal of molecular sciences 2023; (24(16)) doi:10.3390/ijms241612737.

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    A Novel Synonymous Variant of PAX2 in Monochorionic Diamniotic Twins With Bilateral Renal Agenesis: A Case Report and Literature Review.

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    Three New PAX2 Gene Mutations in Patients with Papillorenal Syndrome.

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    Hypoparathyroidism, deafness, and renal dysplasia syndrome: 20 Years after the identification of the first GATA3 mutations.

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This page provides educational information about genetic testing for multicystic dysplastic kidney (MCDK). Always consult your child's nephrologist or genetic counselor regarding specific diagnostic tests and care plans.

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