Family planning, testing relatives and counseling
50% transmission risk if a parent carries it. Cascade testing of relatives is the single most useful next step. Prenatal and preimplantation options exist.
The numbers. If one parent carries the deletion, each pregnancy has a 50% chance of passing it on - and 50% of not. If neither parent carries it (a new/de novo deletion), the chance for future children is low but not zero.
Why test relatives? Because a carrier relative may have no symptoms but still benefit from blood pressure checks, kidney blood tests and yearly glucose checks. Catching diabetes or kidney changes early in an undiagnosed adult relative is a concrete, cheap benefit. This is called cascade testing.
Options if a family wants to avoid passing it on:
- Prenatal testing (CVS at ~11-13 weeks or amniocentesis from ~15 weeks) with targeted testing for
the known family deletion.
- Preimplantation genetic testing (PGT-SR) with IVF - testing embryos before transfer. Availability
and funding vary by country.
- Natural conception with early paediatric follow-up - a completely legitimate choice, especially
given how variable the condition is.
What good counseling does: explains the variability honestly (including that mild cases are common), discusses the range of outcomes without pushing a decision, and gives the family a written report and a copy of the deletion coordinates to pass on.
Freshest finding: A source describes a new or expanded observation: “In this report, we describe a 12-year-old Japanese female with early-onset diabetes mellitus, pancreatic hypoplasia, and multiple renal cysts, harboring a novel de novo HNF1B missense variant (p.Met160Thr) located within the POU-specific domain.”
Counseling points that recur in the literature
- Variable expressivity is the headline. Counselors report that families most often want to know
that the parent's mild presentation does not predict the child's, and vice versa.
- De novo vs inherited matters. Roughly a third to half of cases are de novo; parental testing is
required to know which, and it changes recurrence risk from ~50% to low.
- Prenatal findings are hard to counsel. Deletions found incidentally on screening/placental
testing carry the same variability problem; published series emphasise non-directive counseling and parental phenotyping (including ultrasound) before decisions.
- Adult relatives. Testing adult brothers/sisters of a carrier can be clinically useful; consent
and privacy need handling by a genetics service.
- Documentation. Families should keep the lab report with coordinates; it prevents repeat testing
and is what any future clinician will ask for.
Practical wording for other clinicians
"Chromosomal microarray shows a ~1.4 Mb interstitial deletion at 17q12 including HNF1B and LHX1 (de novo / inherited from mother). This is the 17q12 recurrent deletion syndrome. Please arrange renal surveillance and annual glucose screening; see GeneReviews NBK401562 for the surveillance schedule."
Latest evidence in the collected corpus
New observation reported: In this report, we describe a 12-year-old Japanese female with early-onset diabetes mellitus, pancreatic hypop…
A source describes a new or expanded observation: “In this report, we describe a 12-year-old Japanese female with early-onset diabetes mellitus, pancreatic hypoplasia, and multiple renal cysts, harboring a novel de novo HNF1B missense variant (p.Met160Thr) located within the POU-specific domain.”
“In this report, we describe a 12-year-old Japanese female with early-onset diabetes mellitus, pancreatic hypoplasia, and multiple renal cysts, harboring a novel de novo HNF1B missense variant (p.Met160Thr) located within the POU-specific domain.”corroboration 1 · confidence 97% · updated 2026-11-14 · source
New observation reported: We report a novel in-frame deletion of HNF1B in a family with renal cysts and MODY, furthering our understandi…
A source describes a new or expanded observation: “We report a novel in-frame deletion of HNF1B in a family with renal cysts and MODY, furthering our understanding of HNF1B -related phenotypes.”
“We report a novel in-frame deletion of HNF1B in a family with renal cysts and MODY, furthering our understanding of HNF1B -related phenotypes.”corroboration 1 · confidence 97% · updated 2026-11-14 · source
New observation reported: Here, we report a novel in-frame deletion of HNF1B in a family with renal cysts and MODY, furthering our under…
A source describes a new or expanded observation: “Here, we report a novel in-frame deletion of HNF1B in a family with renal cysts and MODY, furthering our understanding of HNF1B -related phenotypes.”
“Here, we report a novel in-frame deletion of HNF1B in a family with renal cysts and MODY, furthering our understanding of HNF1B -related phenotypes.”corroboration 1 · confidence 97% · updated 2026-11-14 · source
New observation reported: In conclusion, here we report a novel model of non-small cell lung cancer driven by a mutation in Kras and del…
A source describes a new or expanded observation: “In conclusion, here we report a novel model of non-small cell lung cancer driven by a mutation in Kras and deletion of Mst1/2 kinases.”
“In conclusion, here we report a novel model of non-small cell lung cancer driven by a mutation in Kras and deletion of Mst1/2 kinases.”corroboration 1 · confidence 97% · updated 2026-11-14 · source
New observation reported: Here, we report a novel case of a syndromic HNF1B -deficient paediatric patient that developed HCC with unique…
A source describes a new or expanded observation: “Here, we report a novel case of a syndromic HNF1B -deficient paediatric patient that developed HCC with unique histopathological features characterised by neoplastic syncytial giant cells, which was observed only in one additional case of paediatric cholestatic liver disease of unknown origin.”
“Here, we report a novel case of a syndromic HNF1B -deficient paediatric patient that developed HCC with unique histopathological features characterised by neoplastic syncytial giant cells, which was observed only in one additional case of paediatric…”corroboration 1 · confidence 97% · updated 2026-11-14 · source
New observation reported: The current study describes the first case of MODY 5 treated with the GLP-1RA, liraglutide, which exerted prot…
A source describes a new or expanded observation: “The current study describes the first case of MODY 5 treated with the GLP-1RA, liraglutide, which exerted protective effects against pancreatic beta cell dysfunction. [ 11 , 12 ] 2 Case report A 17-year-old woman with a 3-month history of thirst, polydipsia, and polyuria underwent urine glucose scre”
“The current study describes the first case of MODY 5 treated with the GLP-1RA, liraglutide, which exerted protective effects against pancreatic beta cell dysfunction. [ 11 , 12 ] 2 Case report A 17-year-old woman with a 3-month history of thirst, polydipsia,…”corroboration 1 · confidence 97% · updated 2026-11-14 · source
New observation reported: Here, we described five new patients in four families with dup3q29 ranging from 232 to 486 kb in size; based o…
A source describes a new or expanded observation: “Here, we described five new patients in four families with dup3q29 ranging from 232 to 486 kb in size; based on the analysis of our own results and published data, we delineated for the first time the smallest MOR, including only the BDH1 gene, and compared the phenotypes of carriers of reciprocal m”
“Here, we described five new patients in four families with dup3q29 ranging from 232 to 486 kb in size; based on the analysis of our own results and published data, we delineated for the first time the smallest MOR, including only the BDH1 gene, and compared…”corroboration 1 · confidence 97% · updated 2026-11-14 · source
New observation reported: We reported for the first time three patients with cardiac and great artery malformations…
A source describes a new or expanded observation: “We reported for the first time three patients with cardiac and great artery malformations.”
“We reported for the first time three patients with cardiac and great artery malformations.”corroboration 1 · confidence 97% · updated 2026-11-14 · source
This entry is version 15. The analytical engine only appends the clearly-labelled “Latest evidence” section; the text above is curated and is not rewritten by the machine. Confidence 80% · last updated 2026-11-14 16:44