Friday, 29 July 2011

History of Medical genetics II

The 17th-century English Physician Kenelm Digby noted the presence of the double thumb in a n Algerian Muslim family, a trait that reportedly occured in five generations and was confined to females, although Digby personally observed only mother and daughter.

The earliest definitive example, however, was that published by Pierre Louis de Maupertius (whose more theoretical contributions are noted later). In 1753, he described a German family (the proband was a Berlin surgeon named Ruhe) in whom extra digits were inherited through four generations. Maupertius specifically nored that traits was trasmitted equally by father and mother.

He also estimate that if polydactyly had a frequency of 1 in 20000 in the general population, the likelihood of its appearing by chance in three subsequent generations is 1 in 8 trillion. However, his estimate should not be taken as precise, because his ascertainment of polydactyly undoubtedly depended on the occurence of multiple cases- although, whatever allownace one makes for this, there is still a convincing departure from chance!

History of Medical Genetics I

Before Mendel time (1)

The study of inherited disorders represents the core of medical genetics. It is quite clear, however, that specific observations on inherited disorders and more general thoughts about human inheritance have been at the fore-front of concepts of heredity at the very beginning, and do not represent just an afterthoughts o nlate arrival.

The period of before Mendel is the entire period up to the end of the 19th century, during the latter part of which Mendel's work already existed but remained unknown, and have left a discussion of Mendel's own contribution at the end.

Early family reports of some disorders now recoginzed as following Mendelian Inheritance Patterns

Autosomal dominant
Double Thumb                                  Digby 1645
Polydactyly                                       Maupertius 1753
Progressive blindness                        Martin 1809

Autosomal recessive
Albinism                                           Wafer 1699
Congenital deafness                          WIlde 1853
Congenital cataract                           Adams 1814

Color blindness                                Dalton 1798
Hemophilia                                       Otto 1803
Dechenned Muscular Dystrophy       Meryon 1852

Source: A Short History of Medical Genetics: Peter Harper

Genetics training: combined internal medicine/medical genetics

Internal Medicine / Medical Genetics Policies
The American Board of Internal Medicine and the American Board of Medical Genetics offer dual Certification in internal medicine and medical genetics. A combined residency includes a total of five years of coherent training integral to residencies in the two disciplines. The participating residencies must be within a single institution and its affiliated hospitals.

Both Boards encourage residents to extend their training for an additional sixth year in investigative, administrative or academic pursuits in order to prepare graduates of combined training in medial genetics and internal medicine programs for careers in research, teaching or departmental administration.

To meet the eligibility requirements for the Certification processes in internal medicine and medical genetics, the resident must satisfactorily complete 60 months of combined training leading to satisfactory performance in the six competencies that is verified by the director and associate director or the co-directors of these combined training programs.

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