StudyRareStudyRare

What's New

A running log of meaningful additions and changes to StudyRare.

August 2026

Content

  • Von Hippel-Lindau syndrome now carries one mnemonic instead of three: HIPPEL sits inside the name and holds the whole tumor spectrum.
  • Von Hippel-Lindau also gained a Mechanism section, because the mechanism is the shortcut to the phenotype. Losing pVHL stops HIF-2 alpha being degraded, so VEGF and EPO run unopposed, which is why every lesion on the list is hypervascular or cystic and why belzutifan, a HIF-2 alpha inhibitor, treats the driver rather than each tumor in turn.
  • Management for Von Hippel-Lindau now covers belzutifan alongside the surveillance schedule, including why anemia is its expected on-target effect and the contraception conversation to have before the first dose.
  • Nail-patella syndrome now shows a triangular lunula beside a normal one, so the pathognomonic finding is recognizable on sight.
  • New Mitochondrial Genome topic: genome organization, heteroplasmy and the threshold effect, replicative segregation, the germline bottleneck, and why most mitochondrial disease genes are nuclear, with the video lesson built in.
  • Added 36 counseling topics spanning psychosocial care, communication skills, counseling models, professional practice, public health, and research ethics, including the Reciprocal Engagement Model, motivational interviewing, working with interpreters, billing codes, and grief, loss, and adaptation.
  • Added a Client Resources chapter: financial assistance, advocacy organizations, peer support, evaluating resource quality, and community services.
  • Added six metabolic leaves covering gaps in the biochemical genetics outline: serine biosynthesis disorders, hereditary orotic aciduria, molybdenum cofactor deficiency, cerebral creatine deficiency syndromes, pyruvate kinase deficiency, ketone body metabolism disorders, and 3-MCC deficiency.
  • Serine biosynthesis disorders explains why the plasma amino acid panel is normal and only paired CSF shows the deficiency. It is one of the very few treatable causes of congenital microcephaly, and Neu-Laxova syndrome is the severe end of the same spectrum rather than a separate condition.
  • Hereditary orotic aciduria carries the discriminator that matters: orotic acid with a normal ammonia and a megaloblastic anemia that B12 and folate do not fix, against orotic acid with a high ammonia in OTC deficiency.
  • Ketone body metabolism disorders is organised around one contrast. Cannot make ketones gives hypoketotic hypoglycemia; cannot use them gives ketoacidosis with a normal glucose.
  • 3-MCC deficiency covers the full C5-OH differential, because biotinidase and holocarboxylase synthetase deficiency are both biotin-responsive and are the two you cannot afford to miss behind that screening result.
  • Multifactorial inheritance now uses autism as its worked example of the Carter effect, and flags that the familiar 2 to 5% sibling recurrence is a default rather than a rule. Autism runs about 10 to 20%, and quoting the low figure is a common counseling error.
  • Added Nail-patella syndrome. The nail, patella, elbow, and iliac horn tetrad, the radial-to-ulnar nail gradient that puts the worst changes on the thumb, the nephropathy that decides long-term outcome, and the LMX1B homeodomain variants that cause kidney disease with no skeletal findings at all.
  • Added Biotinidase deficiency. Why a vitamin recycling defect produces an organic acid pattern, how to separate it from holocarboxylase synthetase deficiency at the bench, which findings do not reverse on treatment, and the fact that biotin at treatment doses skews troponin and thyroid immunoassays.
  • Added Pulmonary fibrosis. Adult fibrosis is worked up through the marrow and the liver first, because telomere biology disorders scatter fibrosis, low blood counts, and cirrhosis across a pedigree that looks unrelated. Infant and childhood disease runs on a separate surfactant gene list.
  • Added Autism spectrum disorder. The sibling recurrence figure families actually ask for, roughly 10 to 20% rather than the generic multifactorial 3 to 5%, how a female proband and an identified cause change it, and the diagnostic yield of each first-tier test.
  • Added Clonal hematopoiesis. Why an apparent germline TP53 result in blood may be a marrow clone, why saliva and buccal swabs cannot settle the question, and where clonal hematopoiesis surfaces as a false positive on liquid biopsy and on prenatal cell-free DNA screening.
  • Turner syndrome now explains which piece of the X predicts which phenotype, including the ring X that has lost XIST and therefore does cause intellectual disability, unlike standard 45,X.
  • Identity testing now covers biological chimerism: tetragametic chimerism presenting as a difference of sex development, twin-to-twin blood chimerism that can make a paternity test appear to exclude a true father, and how STR profiling tells chimerism from mosaicism.
  • Searching for "unequal crossing over" now finds Structural rearrangements and NAHR, and "long contiguous stretch of homozygosity" now finds Chromosomal microarray. Both pages already taught the concept under a different name.
  • Wolman disease now explains the mechanism. Cholesteryl esters cannot be freed inside the lysosome, so the cell reads itself as cholesterol starved, makes and imports more, and feeds its own storage. The section also says why the adrenal cortex is the tissue that calcifies, and how the block differs from Niemann-Pick type C.
  • Added the WOLMAN mnemonic to Wolman disease: WithOut Lipase, Mineralized Adrenals in Newborn. It holds the missing enzyme and the adrenal calcifications in one hook.
  • Added the L1 syndrome mnemonic Short. The hydrocephalus case, the L1CAM locus, and the L1QUID mnemonic now play right inside the page's Mnemonics section.
  • Added the Sotos syndrome mnemonic Short. The animated case, the NSD1 locus, and the "Not Small, Delayed" mnemonic now play right inside the page's Mnemonics section.

Platform

  • One search bar across the whole library. Clinical Presentations, Counseling, Genetics Principles, Laboratory, and Quantitative Genetics each had a second search box below the main one; they now use the library search at the top of every page, which indexes those sections more deeply anyway. Conditions has worked this way since May.
  • The Reviewed and Not Reviewed filter chips on those five sections no longer slide behind the library search bar when you scroll.