Fingerprints – You are unique like your fingerprints

 

“Life is like a fingerprint that can’t be changed so make the best impression with it. – Unknown.”

 

“Fingerprints have been used for years as the accepted tool in criminology and for identification. The first system of classification of fingerprints was introduced by Jan Evangelista Purkynje (1787-1869), a Czech physiologist, in 1823. He divided the papillary lines into nine types, based on their geometric arrangement. This work, however, was not recognized internationally for many years. In 1858, Sir William Herschel (1833-1917) registered fingerprints for those signing documents at the Indian magistrate’s office in Jungipoor. Henry Faulds (1843-1930) in 1880 proposed using ink for fingerprint determination and people identification, and Francis Galton (1822-1911) collected 8000 fingerprints and developed their classification based on the spirals, loops, and arches. In 1892, Juan Vucetich (1858-1925) created his own fingerprint identification system and proved that a woman was responsible for killing two of her sons. In 1896, a London police officer Edward Henry (1850-1931) expanded on earlier systems of classification and used papillary lines to identify criminals; it was his system that was adopted by the forensic world.”   Jan Evangelista Purkynje (1787-1869): first to describe fingerprints

arch

Image of Arch pattern (Photo Collection: Dr Sampurna Roy MD)

Tiny ridges and furrows are arranged in distinct patterns at the tip of our fingers and thumbs. No one in the world has fingerprint patterns exactly like that of anyone else in every detail. Even the finger prints of identical twins are not exactly the same. These patterns never  change throughout the life, although the skin may become wrinkled and cracked with old age. If the ridges are examined by magnifying glass, it can be seen that each ridge is studded with small holes. These holes are openings from which sweat escapes from the glands situated below the surface of the skin. When a finger is pressed on some smooth object the small deposits of sweat join together and a picture of the ridges in sweat is left behind. These sweat prints are called “latent prints”. The word “latent” is used to indicate hidden, as the prints are difficult to see.  Powder method for detecting latent fingerprints: a review. 

whorl

Image of Whorl pattern (Photo collection Dr Sampurna Roy MD).

Because each person has his or her own fingerprints, they are  obviously an excellent method of identifying people. Fingerprints play an important role in forensic medicine. When a crime is committed, detectives search the scene of the crime look for fingerprints and if they identify any they have a most important clue as to the identity of the criminal. The scientific study of fingerprints is called dermatoglyphics.

“The comparison and identification of crime scene fingerprints is based on human decision making, not a computer algorithm. When a print is lifted from the scene of a crime, it is sent to a professional fingerprint examiner who compares the print to that of a suspect or to the output of a database search. But the ultimate decision about whether the prints came from the same person or two different people is up to the examiner. Fingerprint examiners, with careers often spanning decades, spend several hours a day examining these highly structured fingerprint impressions, which makes them a fascinating expert group for study in their own right. These examiners, however, have testified in court for the past one hundred years as to whether two fingerprints from the same person or different people in the absence of formal data on the extent to which they can correctly match fingerprints to one another” The nature of expertise in fingerprint matching: experts can do a lot with a little.

composite

Image of Composite pattern:  (Photo collection Dr Sampurna Roy MD).

Edward Henry found after many years of work, a method of classifying fingerprints. These are divided into 4 main types – Arch ; Loop ; Whorl and Composite. Every fingerprint belongs to one of these four groups but no two prints have the the same ridge characteristics.

Fingerprints are effectively used for sex determination.

loop

Image of Loop Pattern (Photo collection Dr Sampurna Roy MD).

As a histopathologist one should carefully hold the glass slides at the edge. If  you are sitting behind a pile of urgent slides and in a hurry, please do not press your finger at the centre of the coverslip. The finger tip will leave an imprint on the slide causing blurry microscopic image.  I know someone who did this !!!

There are two important conditions  where patients are born without fingerprints.

1) Adermoglyphia  (immigration delay disease):

Adermatoglyphia or “immigration delay disease”: the role of mutations in the SMARCAD1 gene

2) Naegeli-Franceschetti-Jadassohn  syndrome:

Naegeli-Franceschetti-Jadassohn syndrome in a Saudi Arabian family.

The gene for Naegeli-Franceschetti-Jadassohn syndrome maps to 17q21.

”  Our fingerprints cannot be erased from the lives of those we have touched. -Unknown ”

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