- The interest of the scientific community for handresearch has resulted in a large number of studies focussed on the onset of the skinpatterns (dermatoglyphics) and the palmar creases. Many of these studies indicate that the so-called ‘volar pads’ play an important part in the hand developement - more specific: in the development of the dermatoglyphics and palmar creases: see figure A-6. The fetal ‘volar pads’ can be described as little pillows in the foetal hand, which rise only temporary on the surface of the skin before the permanent manifestation of the dermatoglyphics.

- In the year 1887 Blaschko noticed the relationship between the dermatoglyphics and the ‘ volar pads ’ already - an important issue to understand the hand development.1 However, the work of Bonnvie describes this relationship much more convincing.2 Bonnevie relates e.g. the height of the ‘volar pads’ and the dermatoglyphic pattern type: arches are preceeded with small ‘volar pads’ which develop in a relative late fetal timespan. Loop are preceeded with higer ‘volar pads’ , and whorls are preceeded with relatively high ‘volar pads’ which develop in a relative early fetal timespan.

- - Figure A-6: photo of a 10 week fetal hand.

- - Figure A-7: ‘phantom-picture' related to Down's syndrome.

- In the scientific vocabulary the patterns of the skin on the palms and soles are described with the verb ‘dermatoglyphics’ (dermatoglyphs). This terminology was introduced in the 20's by Harold Cummins. However, this is not the only reason why Cummins is sometimes mentioned as ‘the father of the dermatoglyphics’. For his dermatoglyphic observations in Down's syndrome3-4 can be considered as another milestone in the history of the medical sciences. But the importance of Cummins observations was not fully recognized before the discovery of the genetic cause of Down's syndrome - about 20 years after Cummins major discovery! Some of the palmar stereotypes of Down's syndrome are shown in the 'phantom-picture' which was published by Penrose in 1963 in the well-known scientific magazine 'Nature'.5