Video: introduction to Down syndrome
- NORMAL HAND LINES - vs. - THE SIMIAN LINE -
SIMIAN LINE INDEX:
INTRO: About the Simian Line (a.k.a. 'simian crease')
• HOW TO RECOGNIZE a 'complete' Simian Line?
• WHY PALM CREASE NAMED the Simian Line?
• BRIEF HISTORY of the Simian Line
• ETHNIC POPULATIONS & the Simian Line
• MEDICAL PROBLEMS & the Simian Line
• PSYCHOLOGY & the Simian Line
• PROJECTS related to the Simian Line
• SYNONYMS for the Simian Line
• FAMOUS Simian Line holders
SIMIAN LINE & DIAGNOSTICS:
• The Simian Line in DOWN SYNDROME!
• The Simian Line in FRAGILE X SYNDROME!
_(In autism 2% to 6% have Fragile X syndrome!)
MORE HAND DIAGNOSTICS:
• The hand lines (palmar creases)
• The Sydney line
• The Hypothenar whorl
• The 5th finger (pinky)
• The fingernail tutor
ABOUT THE USE OF THE FAMOUS 'SINGLE PALMAR CREASE' AS A NOTORIOUS MARKER IN HAND DIAGNOSTICS
the Simian Line & 27 markers in Down syndrome!
Many studies around the world have proven that the simian line is a very common hand characteristic in Down's syndrome. But other studies have indicated that the simian line is also recognized as a (very) common characteristic in other genetic syndrome - and one should also not forget that simian lines can also be observed in about 3% of the healthy population.
This raises the question: 'how can the simian line serve as a diagnostic marker specific for Down's syndrome?'
In 1963 L.S. Penrose presented the first 'phantom picture' describing the typical hand characteristics in Down syndrome. More detailed 'phantom pictures' were presented by Schaumann & Alter (1976), Rodewald (1981).
Combined with other sources, the author presents an updated comprehensive 'phantom picture' for the most typical hand-characteristics in Down syndrome.
'Phantom picture' of the hand in Down's syndrome: 27 typical characteristics.
During the 20th century quite a few studies have pointed out that in Down syndrome the simian line is always featured with a combination of other characteristics in 3 dimensions of the hand:
A - Hand lines (including: palms & fingers);
B - Dermatoglyphics (including: fingerprints & palmar ridge patterns);
C - Hand morphology (including: finger length & hand shape).
An overview of the details (see also the 'phantom picture' above):
A - HAND LINES IN DOWN SYNDROME (1-4):
• 1 - Simian crease - in both hands!
|
Prevalence: Down patients - males: 28.3 %, females: 23.4 %; controls: 4.0 % & 1.5 %1
NOTICE: Other studies 2 have indicated that the simian is also very significant when present only in the right hand; when present only in the left hand it is especially significant when combined with a Sydney line in the right hand. | ||
• 2 - Sydney line - in both hands!
|
Prevalence: Down patients - males: 15.2 %, females: 17.4 %; controls: 5.5 % & 2.0 % 1
NOTICE: Other studies 2 have indicated that the Sydney line (= extended 'head line') is also very signficant if present in only one hand when combined with a simian crease in the other hand - especially when the Sydney line is present in the left hand. | ||
• 3 - Distal transverse crease [heart line]: extended
|
Prevalence: Down patients: ? (unknown %); controls: rare (unknown %)
NOTICE: A study 2 has indicated that the extend distal transverse crease (= extended 'heart line') is signficant when observed in the left hand; in the right hand it is significant when combined with a simian crease in the left hand. | ||
• 4 - 5Th finger: single crease
|
Prevalence: Down patients: 11.5 %; controls: 0 % 3
NOTICE: Other studies from 7 different countries4 reported percentages in Down samples varying from 8.6 % to 37.7%. | ||
B - HAND DERMATOGLYPHICS IN DOWN SYNDROME (5-20):
• 5 - Fingerprints: 10 ulnar loops
|
Prevalence: Down patients - UK: 34.5 %, Japan: 29.0 %; controls: 5.5 % & 5.7 % 4
NOTICE: The ulnar loops in Down syndrome tend to be vertically oriented and L-shaped - with the 'open' side directed to the side of the pinky finger. Another common variant is: 9 (or 8) ulnar loops combined with a radial loop on the ring finger or pinky finger. | ||
• 6 - Fingerprints: radial loops on ring finger
|
Prevalence (8 populations): Down patients - 2.0 to 22.2 % 4; controls: 0 % to 5.7 % 5 NOTICE: In Down syndrome the radial loop is most frequently seen on the ring finger (the radial loops are usually vertically oriented and L shaped - with the 'open' side directed to the side of the thumb. A radial loop on the thumb, index finger or middle finger should be recognized as a 'contra-indication' towards Down syndrome. | ||
• 7 - Fingerprints: radial loops on the pinky finger
|
Prevalence (6 populations): Down patients - 0 to 9.0 % 4; controls: 0 % to 1.5 % 5
NOTICE: In Down syndrome the radial loop on 5th finger (pinkie) is more frequently seen than radial loops on the middle finger (in the general population the reverse is always observed). | ||
• 8 - Palmar ridge line A: ends between pinky finger & distal transverse crease - in both hands!
|
Prevalence: Down patients: 29.3 %; controls: 0.7 % 6
NOTICE: The 'palmar ridge line A' starts in the triradius below the pointer finger. In Down syndrome the path of the 'palmar ridge line A' ends often just above or close to the point where the 'upper transverse crease' (heart line) exits the palm. In the normal population the path of the 'palmar ridge line A' is usually found completely below the 'upper transverse crease'. | ||
• 9 - Palmar ridge line B: ends between pinky & ring finger - in both hands!
|
Prevalence: Down patients: 64.7 %; controls: 23.0 % 6
NOTICE: The 'palmar ridge line B' starts in the triradius below the middle finger. In Down syndrome the 'palmar ridge line B' ends usually in both hands at the edge of the palm between the pinky finger and the ring finger. While in the normal population more variation is observed. | ||
• 10 - Palmar ridge line C: ends between ring- & middle finger in both hands
|
Prevalence: Down patients: 46.7 %; controls: 19.6 % 6
NOTICE: The 'palmar ridge line C' starts in the triradius below the ring finger. In Down syndrome the path of the 'palmar ridge line C' usually creates an 'interdigital loop', and exits the palm at a point between the ring finger and the middle finger. In the normal population this is a common pattern as well, but other variation are much more often seen. | ||
• 11 - Palmar triradius C (left hand): missing or 'abortive'
|
Prevalence: Down patients - 48.5 % to 54.9 %; controls: 14.1 % to 15.0 % 4
NOTICE: The 'palmar triradius C' concerns the palmar triradius that is usually positioned below the ring finger. In Down syndrome this triradius is often missing in the left hand, or the related 'palmar ridge line C' is ending without researching the border of the palm. This characteristic is far less often seen in the righ hand (in both Down patients and the normal population). | ||
• 12 - Palmar ridge line D: radial exit [between pointer finger & thumb]
|
Prevalence: Down patients - 3.0 % to 3.9 %; controls: 0 % to 0.5 % 4
NOTICE: The 'palmar ridge line D' starts in the triradius below the pinky finger. In Down syndrome the 'palmar ridge line D' occasionally ends at the thumb side of the palm (while in the normal population the 'palmar ridge line D' usually ends somewhere between the fingers). | ||
• 13 - Alignment of ridges over the distal palmar area: 'transverse'
|
Prevalence - Down patients: high (unknown %); controls: low (unknown %)
NOTICE: In Down syndrome the alignment of ridges over the distal palmar area is - partly due to the short, broad hand shape - nearly always rather 'transverse' (horizontal). This is usually indicated by the combination of a 'palmar ridge line A' which exits the palm above (or just below) the heart line, combined with a 'palmar ridge line D' which exits the palm between the pointer finger and the middle finger. | ||
• 14 - Palmar axial triradius: atd angle 57o or larger
|
Prevalence: Down patients - males: 79.6 %; females: 81.2 %; controls: 6.9 %, 7.7 % 4
NOTICE: It is important to notice that the atd angle is an age dependent characteristic (children have larger atd angles than adults). In Down syndrome adults a high displaced axial triradius (t") is often featured with a large AtD angle: 57o or higher. | ||
• 15 - Palmar axial triradius: distally displaced (t")
|
Prevalence: Down patients - 44.5 % to 87.0 %; controls: 1.6 % to 11.8 % 4
NOTICE: In Down syndrome the high displaced axial triradius (t") is often found in a position close to the center of the palm. Usually this high positioned triradius is featured with a pattern on the hypothenar [mount of moon] + another triradius (often postitioned near the wrist (t) or higher (t')). | ||
• 16 - Hypothenar [mount of moon]: 3 or more triradii
|
Prevalence: Down patients: 4.9 %; controls: 0 % 6
NOTICE: In Down syndrome quite often 3 or more triraii can be observed on the hypothenar [mount of moon] - due to the presence of various types of large loops, mulitple loops, or whorls. | ||
• 17 - Hypothenar [mount of moon]: whorl
|
Prevalence: Down patients - 3.9 % to 16.8; controls: 0.9 % to 4.7 % 1
NOTICE: In Down syndrome a large hypothenar whorl is relatively common. The hypothenar whorl is particularly significant when observed in both hands; or when observed in one hand but combined with a large hypothenar ulnar loop in the other hand. Double loops are very rarely seen in Down's syndrome, and are more common in the general population (where they are rare as well). | ||
• 18 - Hypothenar [mount of moon]: large ulnar loops
|
Prevalence: Down patients - males: 49.1 %, female: 45.0 %; controls - males: 1.9 %, females: 6.4 % 4
NOTICE: In Down syndrome the large ulnar loops are by far the most common seen patterns on the hypothenar [mount of moon]; and especially when there is only 1 loop present on the hypothenar it is nearly always an ulnar loop. While in the general population hypothenar radial loops are much more common compared to hypothenar ulnar loops. | ||
• 19 - Dysplasia: palmar ridge dissociation [broken skin ridges]
|
Prevalence: Down patients: 50.0%; controls: 4.0 % 4
NOTICE: Ridge dissociation concerns poor formation of the palmar ridges, resulting in skin ridge lines of which the direction is difficult to follow. In Down syndrome ridge dissociation is a very common characteristic that is often found in large parts of the palms (sometimes the full palm). | ||
• 20 - Thenar [mount of venus]: no pattern
|
Prevalence: Down patients - 99.3 % to 96.0%; controls: 95.4 % to 88.3 % 4
NOTICE: In Down syndrome there are usually no loops or whorl observed on the thenar [mount of venus]; in the normal population those patterns are more common. | ||
C - HAND MORPHOLOGY IN DOWN SYNDROME (21-27):
• 21 - Thumb: short, low set position
|
Prevalence - Down patients: high (unknown %); controls: low (unknown %) 7
NOTICE: In Down syndrome the short, low set thumb is also featured with minor motoric hand gesture & closure inabilities. | ||
• 22 - Pinky finger: short
|
Prevalence: Down patients: 51% - 77%; controls: low (unknown %) 8
NOTICE: In Down syndrome the length of the pinky finger is sometimes shorter than half of the palm length. | ||
• 23 - Pinky finger: clinodactyly [incurved]
|
Prevalence: Down patients: 25% - 77% 8,9; controls: 10 % 9
NOTICE: In Down syndrome the (short) incurved pinkie is quite common. One should notice here as well that clinodactyly is not considered as a (severe) hand anomaly. | ||
• 24 - Fingers: brachydactyly [abnormally short fingers]
|
Prevalence: Down patients: 11 % to 72.3 % 10; controls: near 1 %
NOTICE: It is important to notice that relative finger length is an age dependent characteristic (children have relatively shorter fingers than adults). In Down syndrome the fingers are usually short, frequently 'abnormally short' (according the Mehes scales 'abnormally short fingers' are defined as: middle finger length is shorter than 40% of full hand length; full length hand is measured from the tip of the middle finger to the distal flexor crease of the wrist). | ||
• 25 - Fingers: hyperextensible finger joints
|
Prevalence: Down patients: 80 %; controls: rare (unknown %) 11
NOTICE: Hyperextensible finger joints are associated with a muscle condition named 'muscular hypotonia'. | ||
• 26 - Palm: short, small, but relatively broad
|
Prevalence: Down patients: high (unknown %); controls: low (unknown %)
NOTICE: It is important to notice that palm shape is an age dependent characteristic (children have more square-shaped palms than adults). In Down syndrome the handpalm is usually small, and especially short (compared to body length); but the width of the palm is relatively large. | ||
• 27 - Fingernails: brachyonychia [very short fingernails]
|
Prevalence: Down patients: often (unknown %); controls: low (unknown %) 12
NOTICE: In Down syndrome very short fingernails are often seen, sometimes the complete fingernail is very small (micronychia). Other typical characteristics of the fingernail in Down's syndrome are: no lunula - also in the thumb nail! | ||
SOURCES:
1) Palmar Dermatoglyphics of Down's Syndrome: Revisited. C.C. Plato et al., 1973
2) Het gebruik van dermatoglyfen bij de diagnose van het syndroom van Down. [Dutch language] J.F.M. Deckers, et al., 1973
3) Evaluation of dermal patterns in Down's syndrome by predictive discrimination. D.S. Borgaonkar et al., 1971
4) Dermatoglyphics in medical disorders. B.A. Schaumann & M. ALter, 1976
5) Quantitative dermatoglyphics: classification, genetics, and pathology. D.Z. Loesch, 1983
6) Hautleistenfibel. A. Rodewald & H. zankl, 1981
7) Physical examination of the newborn. L.L.McCollum, 2009
8) Primary Care of Infants and Young Children with Down Syndrome. R.B. Saenz, 1999
9) Clinodactyly. Children's hospital Boston, 2009
10) Down Syndrome in Estonia. T. Reimand, 2007
11) Clinical features of Down syndrome in neonates. S. Kolpuru, 2007
12) Color atlas of the nail in clinical diagnosis. D.W. Beaven & S.E. Brooks, 1984
in hand diagnostics for Down syndrome?
It is important to notice here that not all hand characteristics are equally significant for recognizing Down syndrome.
Specific indications for the significance of specific hand characterstics are provided by the prevalence of these hand characterstics in the control groups: the most significant hand characteristics are found in those which show a relatively large %-difference between the Down patients and the control groups.
The following ten hand characteristics have frequently shown a 10-times higher prevalence percentage in Down groups (compared to the control group): no.1, no.4, no.8, no.12, no.13, no.14, no.15, no.18, no.19, and no.24. So, these hand characteristics belong to the most significant hand zones to focuss on for recognizing Down syndrome!
The simian crease (1) is included, but the combination of: the position of the 'palmar axial triradius' (14 & 15); plus the 'transversal' alignment of the palmar ridge lines A to D; plus the fingerprint of the pointer finger (and ring finger) are probably the most common significant hand characteristic in Down syndrome!
In general, if any hand presents a combination of multiple characterstics in EACH single of the 3 dimensions (hand lines, hand dermatoglyphics & hand shape), than it is very likely that the hand belongs to a person who has Down's syndrome.
For people who have the simian line in both hands, one can determine the significance for Down syndrome by studying the other hand characteristics. Only when the hands are also featured with the following combination, one can make a hand-diagnosis for Down syndrome:
- (1) mulitiple characteristics from dimension B (hand dermatoglyphics no.5 to no.20: combinations of both palm- and finger characteristics are required),
- (2) plus multiple characteristics from dimenion C (hand morphology no.21 to no.27: combinations of both palm- and finger characteristics are required).
So, if those people have a simian line in both hands, they also need to have a 'wide' range of significant combinations - in both their palms AND their fingers - before one can speak of an thorough & complete 'hand diagnosis' for Down syndrome!!!
Estimate: those people have a statistical chance of about 99% that a chromosomal test [= genetic testing] will reveal that they have 'trisomy 21'! (= the genetic disorder which is responsible for the manifestation of Down's syndrome).
FINAL NOTIFICATION:
Below are two illustrative cases - featured with high-resolution hand materials - of 2 men who have Down syndrome.
Down syndrome case 1:
|
Down syndrome case 2:
|
What is in 2010 the state of knowledge about simian lines? ...more.