Presentation: Fetus with cystic renal disease

A woman who is 19 weeks pregnant presents for her fetal anomaly screening scan appointment. Ultrasonography of the fetus appears as expected, except for the baby’s right kidney, which contains multiple cysts. The left kidney presents normally.

• Genomic testing should always be considered in cases of cystic renal disease, especially when it is bilateral or associated with other anomalies, in order to estimate the chance of recurrence.
• Prenatal diagnosis can be offered by first-trimester testing in affected families with a known pathogenic variant.

• Explore the woman’s pregnancy, medical and family history.
• Refer to local guidance regarding fetal medicine referral (further review in a fetal medicine unit is usually warranted).
• A fetal medicine review will determine whether genomic testing is appropriate and referral to clinical genetics will be considered.
• The clinical genetics team will review the NHS England National Genomic Test Directory eligibility criteria to determine which tests are available for your patient. The directory itself provides a list of all available tests.
  • For those working within NHS Wales, please consult the All Wales Medical Genomics Service website for information on how to arrange testing.
• Depending on the clinical scenario, a range of different genomic tests may be considered:
  • Where there is a unilateral cystic renal disease, karyotyping is offered:
    • R401 Common aneuploidy testing – prenatal;
    • R401.1 Genome-wide common aneuploidy testing – prenatal; and
    • R22 Fetus with a likely chromosomal abnormality. This will process both:
      • genome-wide common aneuploidy testing; and
      • chromosomal microarray.
  • Where there are multiple or complex anomalies and/or above testing is non-diagnostic, fetal exome sequencing may be considered:
    • R21 Fetal anomalies with a likely genetic cause: Fetal exome sequencing.
    • Referral to clinical genetics and/or multi-disciplinary discussion is required.
    • A record of discussion form is required.
  • For all these tests, an amniocentesis or chorionic villus sample or fetal blood sample (in an EDTA tube) is required. For many of the tests (particularly whole genome and exome sequencing), parental samples are also needed or are helpful. Please refer to your local Genomic Laboratory Hub for details of test request forms and where to send samples.
• Information about patient eligibility and test indications was correct at the time of writing. When requesting a test, please refer to the National Genomic Test Directory to confirm the right test for your patient.

For clinicians

• Fetal Medicine Foundation: Autosomal dominant polycystic kidneys
• Fetal Medicine Foundation: Autosomal recessive polycystic kidneys
• Fetal Medicine Foundation: Multicystic kidneys
• NHS England: National Genomic Test Directory and eligibility criteria

References:

• Alt S, Arezina J, Arnold J and others. ‘Consensus guidelines on the communication of unexpected news via ultrasound.’ White Rose Research Online. DOI: 10.5518/100/24

For patients

• InfoKID: Multicystic dysplastic kidney (MCDK) information
• Massachusetts General Hospital: Fetal multicystic dysplastic kidney (MCDK) information