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Jan Mohr

Jan Mohr is a biology topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Jan Mohr rather than just read about it. In short: Jan Gunnar Faye Mohr (10 January 1921 – 17 March 2009) was a Norwegian-Danish physician and geneticist, known for his discovery of the first cases of autosomal genetic linkage in man, between the Lutheran blood groups and the ABH-secretor system, and between these and the hereditary disease myotonic dystrophy. Besides being first steps in mapping the human genome, the findings illustrated the medical potential of li…

Key takeaways

  • Jan Mohr belongs to biology; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Jan Mohr to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Jan Mohr from memory before moving on to harder problems.

Reference excerpt

Jan Gunnar Faye Mohr (10 January 1921 – 17 March 2009) was a Norwegian-Danish physician and geneticist, known for his discovery of the first cases of autosomal genetic linkage in man, between the Lutheran blood groups and the ABH-secretor system, and between these and the hereditary disease myotonic dystrophy. Besides being first steps in mapping the human genome, the findings illustrated the medical potential of linkage analysis in prenatal genetic diagnosis. Mohr is eponymously known by the syndrome Mohr-Tranebjærg, a progressive deafness with X-linked mode of inheritance, which was first described by Jan Mohr, and then more comprehensively by Tranebjærg et al. The 'Mohr syndrome', or oral-facial-digital syndrome type II, is named after Otto Lous Mohr, uncle of Jan Mohr.

Biography Jan Mohr was born 1921 in Paris. His father was the Norwegian painter Hugo Lous Mohr. Jan Mohr graduated 1948 from medical school, Oslo University. Then, under the Rockefeller Foundation, studied genetics at Columbia University, University College London and the Institute of Medical Genetics, Copenhagen University. In 1954, Mohr was awarded a doctorate at Copenhagen University, and in 1968 became a member of the Royal Danish Academy of Sciences and Letters. At the University of Oslo, he established and directed through the years 1954-1964 the Institute of Medical Genetics, along somewhat similar lines as the Copenhagen Institute. In 1964 he succeeded Tage Kemp in the Chair as Professor of Medical Genetics, Copenhagen University. Together with Hans Eiberg he established Copenhagen Family Bank in 1972, a store of DNA samples, comprising about 1000 large Danish families as a basis for a Resource Center for Linkage analysis, RC-LINK, to study also familial diseases such as cystic fibrosis and Batten disease, both of which are among diseases mapped at the center. In 1968 Mohr introduced the concept of antenatal genetic diagnosis using sampled chorionic villi, and then together with N.Hahnemann developed the approach (for diagnosis early in pregnancy) towards clinical application. Mohr founded and edited until his retirement the journal Clinical Genetics: An International Journal of Genetics in Medicine, as a sequel to the Opera series of the Copenhagen Institute, which had been discontinued. This was in cooperation with his two Nordic colleagues Kåre Berg in Oslo and Jan Arvid Bøøk in Uppsala. In 1966 Mohr was elected founding chairman of European Society of Human Genetics, and managed the Society through following years. As Professor emeritus he pursued his genetic interests under the European Commission as a concerted action project leader within cancer genetics, with participation of research groups from most European countries.

References Mohr, Jan (1951). Search for linkage between the Lurtheran blood groups and other hereditary characters. Acta Path. Microbiol. Scand. 28:207-210 Mohr, Jan (1954). A Study of linkage in man. Opera ex Domo Biol Hered.Humanae Universitatis Hafniensis.Vol 33, Munksgaards Forlag. Copenhagen. Renwick, J.H. and Bolling, D.R. (1971). Mohr's Hat Trick Confirmed. Fourth International Congress of Human Genetics, Paris, 1971 & Renwick, J.H. and Bolling, D.R. (1971). An analysis procedure illustrated on a triple linkage of use for prenatal diagnosis of myotonic dystrophy. J. Medical Genet. 8: 399-406, 1971 Mohr, J. and Magerøy, K. (1960). Sex linked deafness of a possibly new type. Acta Genet. Statist. Med. 10: 54-62 Tranebjærg, L; Schwartz, C., Higgins, K., Barker, D.; Stevenson, R.; Arena, J.F.; Gedde-Dahl, T.; Mikkelsen, M.; Mellgren, S., Andersen, K., Hansen, E.; Dahl, A.; Eriksen, H.; Lubs, H. X-linked recessive mental retardation with progressive sensorineural deafness, blindness, spastic paraplegia and dystonia. Am. J. Hum. Genet. 51(suppl.); A47 only (1992). Eiberg, H., Mohr, J., Schmiegelow, K., Nielsen, L.S., Williamson, R.: Linkage relationships of paraoxonase (PON) with other markers: Indication of PON-cystic fibrosis synteny. Clin Genet 28: 265-271 (1985) Eiberg, H., Gardiner R.M., Mohr, J. Batten disease (Spielmeyer-Sjøgren disease) and haptoglobin: Indication of linkage and assignment to chr.16 Clin Genet 36: 217-218 Mohr, O.L. (1941). A hereditary lethal syndrome in man. Avh. Norske Vidensk. Akad. Oslo 14: 1-18 Dunn, L.C. and Mohr, J. (1952). An association of hereditary eye defects with white spotting. Proc. Natl. Acad. Sci. USA, 38: 872-875 Mohr, J. (1968). Foetal genetic diagnosis. Development of techniques for early sampling of foetal cells. Acta Pathologica Microbiologic. Scandinavia 73: 7377 Hahnemann, N. and Mohr, J. (1969). Antenatal diagnosis in genetic disease. Bulletin of the European Society of Human Genetics, Vol 3, p 47-54 Hahnemann, N. (1974). Early prenatal diagnosis: A study of biopsy techniques and cell culturing techniques from extraembryonic membrane. Clin.Genet., 6, 294-306 Meena Upadhyaya, Alan Fryer, Graham Foat, Denise Robinson, Oliver Quarrell, Adrian Roberts, P.S. Harper (1989). Chorionic villus sampling for prenatal diagnosis in Wales using DNA probes - 5 years experience. Prenatal diagnosis. Vol 10, Issue 9, Pages 593-603 Woo, J. (1990+). A short history of Amniocentesis, Fetoscopy, and Chorionic Villus Sampling (Net).

Bibliography Mohr, J. (1954) A Study of Linkage in Man. Munksgaards Forlag, Copenhagen. Mohr, J. (1982). Arvelighedslære 4 udg. Nyt Nordisk Forlag Arnold Busck, Copenhagen.

Worked examples

Example 1 — a first encounter with Jan Mohr

Start with the simplest possible case. Write down what Jan Mohr claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Jan Mohr before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Jan Mohr ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Jan Mohr

In research
Jan Mohr appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Jan Mohr in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Jan Mohr is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1921 births, 2009 deaths, Danish geneticists, so understanding it makes those chapters shorter.
In everyday life
Look for Jan Mohr outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.
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How to study Jan Mohr in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Jan Mohr means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Jan Mohr out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Jan Mohr in simple terms?

Jan Gunnar Faye Mohr (10 January 1921 – 17 March 2009) was a Norwegian-Danish physician and geneticist, known for his discovery of the first cases of autosomal genetic linkage in man, between the Lutheran blood groups and the ABH-secretor system, and between these and the hereditary disease myotoni…

Why does Jan Mohr matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Jan Mohr?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Jan Mohr.

Tags

  • 1921 births
  • 2009 deaths
  • Danish geneticists
  • Danish scientists
  • Norwegian emigrants to Denmark
  • Norwegian expatriates in England
  • Norwegian expatriates in France
  • Norwegian expatriates in the United States
  • Norwegian geneticists

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