Video: introduction to Fragile-X 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 & 28 markers in fragile-X syndrome!
Various studies around the world have proven that the simian line is a common hand characteristic in fragile-X syndrome. But other studies have indicated that the simian line is also recognized as a common characteristic in other genetic syndromes (e.g. Down 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 Fragile X syndrome?'
In 1986 A. Rodewald et al. presented the first 'phantom picture' describing the typical hand characteristics in Fragile-X syndrome (Xq27).
Combined with other sources, the author presents below an updated comprehensive 'phantom picture' for the most typical hand-characteristics in Fragile-X syndrome.
'Phantom picture' of the hand in Fragile-X syndrome: 28 typical characteristics.
During the 20th century quite a few studies have pointed out that in Fragile-X syndrome the simian line is often 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 FRAGILE-X SYNDROME (1-2):
• 1 - Simian crease
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Prevalence: Fragile X patients - males: 22.0 %, females: 14.3 %; controls: 1.0 % & 1.0 %1 NOTICE: Multiple studies 1,2 have indicated that especially an 'incomplete' simian line is very often observed in the hands of people with Fragile X syndrome - though one should also notice that an incomplete simian line is relatively common. L. Hirth et al. (1985)2 reported a percentage of 73% 'abberant simian creases' in a small sample of Fragile X carriers (N=15), versus 10% in controls (N=200). | ||
• 2 - Sydney line
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Prevalence: Fragile X patients - males: 22.6 %, females: 19.6 %; controls: 0.7 % & 0.7 %1 NOTICE: Multiple studies 1,2 have indicated that especially an 'incomplete' Sydney line is very often observed in the hands of people with Fragile X syndrome - though one should also notice that an incomplete Sydney line is relatively common. L. Hirth et al. (1985)2 reported a percentage of 60% 'abberant Sydney creases' in a small sample of Fragile X carriers (N=15), versus 9% in controls (N=200). | ||
B - HAND DERMATOGLYPHICS IN FRAGILE-X SYNDROME (3-24):
• 3 - Fingerprints: radial loop on thumb
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Prevalence: Fragile X patients - 2.6 %; controls: 0 % 4
NOTICE: A higher prevalence of radial loops on the 1th finger has been noticed in various studies1,4. | ||
• 4 - Fingerprints: radial loop on index finger - in both hands
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Prevalence: Fragile X patients - right hand 21.4 %, left hand 21.4 %; controls - right hand 6.3 %, left hand 12.0 %5
NOTICE: A higher prevalence of whorls on the 3th finger has been noticed in various studies1,4,5. | ||
• 5 - Fingerprints: ulnar loop missing on index finger - in both hands
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Prevalence: Fragile X patients - males: 82.7 % (+ 92.9%); females: 78.6 %; controls - males: 69.3 % (+ 62.3%); females: 68.0% 1+5
NOTICE: A lower prevalence of loops on the 2th finger has been noticed in various studies1,4,5. | ||
• 6 - Fingerprints: radial loop on middle finger
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Prevalence: Fragile X patients - males: 8.5 %, females: 6.9 %; controls: 1.8 %, 1.4 % 3
NOTICE: A higher prevalence of radial loops on the 3th finger has been noticed in various studies1,3,4. | ||
• 7 - Fingerprints: arch on middle finger (in males only)
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Prevalence: Fragile X patients - right hand: 17.3 %; left hand: 17.3 %; controls: 4.2 % and 5.3 % 1
NOTICE: A higher prevalence of arches on the 3th finger has been noticed in various studies1,3,4,5. | ||
• 8 - Fingerprints: whorl on middle finger - in both hands
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Prevalence: Fragile X patients - males: right hand 27.7 %, left hand 27.7 %; females: right hand 25.0 %, left hand 19.4 %; and controls - males: right hand 17.4 %, left hand 15.8 %; females: right hand 9.7 %, left hand 13.4% 3
NOTICE: A higher prevalence of whorls on the 3th finger has been noticed in various studies3,4,5,6. | ||
• 9 - Fingerprints: arch on ring finger (in males only)
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Prevalence: Fragile X patients - right hand: 5.1 %; left hand: 20.5 %; controls: 0.4 % and 2.8 % 4
NOTICE: A higher prevalence of arches on the 4th finger has been noticed in various studies1,4,5. | ||
• 10 - Fingerprints: arch on pinky finger (in males only)
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Prevalence: Fragile X patients - right hand: 7.7 %; left hand: 5.1 %; controls: 0.6 % and 1.0 % 4
NOTICE: A higher prevalence of arches on the 5th finger has been noticed in various studies1,4,5. | ||
• 11 - Palmar ridge line A: ends between pointer finger & middle finger (or returns into the a triradius)
| Prevalence - Fragile X patients: sometimes (unknown %); controls: extremely rare (unknown %) 1 | ||
• 12 - Palmar ridge line A: ends between pinky finger & distal transverse crease - in both hands!
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Prevalence: Fragile X patients - males: 26.7 %, females: 21.4 %; controls: 1.0%,1.0% 1
NOTICE: A higher prevalence of a transverse progression of line A has been noticed in various studies1,5. | ||
• 13 - A-b ridge count < 70 [number of ridge lines between the a triradius (below pointer finger) and b triradius (below middle finger) summarized for both hands]
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Prevalence: Fragile X patients - males: 38.3 %, females: 27.8 %; controls: 11.3 %, 12.7 % 3
NOTICE: A higher prevalence of a low a-b ridge count has been noticed in various studies3,4. | ||
• 14 - Palmar triradius b: missing (or palmar ridge line B is 'abortive')
| Prevalence: Fragile X patients - males: 5.4 %, females: 0 %; controls: 0 %, 0 % 1 | ||
• 15 - Palmar ridge line B: ends between middle finger & ring finger (or returns into the b triradius) - in both hands!
| Prevalence - Fragile X patients: high (unknown %); controls: rare (unknown %) 1 | ||
• 16 - Palmar triradius c: missing in left hand (or both hands)
| Prevalence: Fragile X patients - males: 9.3 %, females: 17.8 %; controls: 3.1 %, 8.0 % 1 | ||
• 17 - Palmar ridge line C: 'abortive' [stops at short distance below triradius c]
| Prevalence: Fragile X patients - males: right hand 13.3 %, left hand 32.0 %; females: right hand 7.1 %, left hand 28.6 %; and controls - males: right hand 0.5 %, left hand 2.5 %; females: right hand 0.5 %, left hand 0.5% 1 | ||
• 18 - Palmar ridge line C: ends between pointer finger & middle finger (or: in/below a triradius)
| Prevalence: Fragile X patients - males: right hand 13.3 %, left hand 2.7 %; females: right hand 0 %, left hand 0 %; and controls - males: right hand 4.2 %, left hand 0.5 %; females: right hand 1.9 %, left hand 0 % 1 | ||
• 19 - Palmar triradius d: missing
| Prevalence: Fragile X patients - males: 4.0 %, females: 0 %; controls: 0.5 %, 0 % 1 | ||
• 20 - Palmar ridge line d: ends below the a triradius [at the thumb side of the palm]
| Prevalence: Fragile X patients - males: 2.7 %, females: 0 %; controls: 0.5 %, 0 % 1 | ||
• 21 - Alignment of ridges over the distal palmar area: 'transverse'
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Prevalence - Fragile X patients: high (unknown %); controls: low (unknown %)
NOTICE: In Fragile X syndrome the alignment of ridges over the distal palmar area is - partly due to the relatively short, broad hand shape - usually 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. | ||
• 22 - Thenar [mount of venus]: radial loop
| Prevalence - Fragile X patients: high (unknown %); controls: rare (unknown %) 1 | ||
• 23 - Full palm: empty hands [absence of true patterns: loops/whorls]
| Prevalence: Fragile X patients - males: right hand 5.3 %, left hand 16.0 %; females: right hand 10.7 %, left hand 7.1 %; and controls - males: right hand 1.8 %, left hand 1.6 %; females: right hand 1.8 %, left hand 1.6 % 1 | ||
• 24 - Dysplasia: palmar ridge dissociation [broken skin ridges]
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Prevalence - Fragile X patients: high (unknown %); controls: low (unknown %) 1
NOTICE: Ridge dissociation concerns poor formation of the palmar ridges, resulting in skin ridge lines of which the direction is difficult to follow. In Fragile X syndrome ridge dissociation is a relatively common characteristic in both the palms and the fingerprints. | ||
C - HAND MORPHOLOGY IN FRAGILE-X SYNDROME (25-28):
• 25 - Fingers: hyperextensible finger joints
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Prevalence: Fragile X patients: 81 %; controls: rare (unknown %) 7
NOTICE: Hyperextensible finger joints are associated with a muscle condition named 'muscular hypotonia'. In fragile X syndrome it may manifest as: metacarpophalangeal extension to 90 degrees or more. | ||
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Prevalence - Fragile X patients: 58 %; controls: low (unknown %) 7
NOTICE: In fragile X syndrome is are unusually flexible thumbs a typical manifestation of a connective tissue disorder. | ||
• 27 - Fingers: relatively long to hand length, short to palm width
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Prevalence: Fragile X patients: high (unknown %); controls: low (unknown %) 2
NOTICE: It is important to notice that relative finger length is an age dependent characteristic (children have relatively shorter fingers than adults). In Fragile X syndrome the fingers are usually long compared to palm length (ratio > 0.45 %), short compared to palm width (ratio < 0.97 %), and slightly long compared to body length (ration > 4.9 %) [Percentages are based on figures provided by the 'Handbook of Physical Measurements']. | ||
• 28 - Palm: relatively broad to palm length and finger length
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Prevalence: Fragile X patients: high (unknown %); controls: low (unknown %) 2
NOTICE: It is important to notice that palm shape is an age dependent characteristic (children have more square-shaped palms than adults). In Fragile X syndrome the handpalm is usually broad compared to palm length (ratio > 0.82 %), finger length (ratio > 1.03 %), and body length (ratio > 5.0 %); [Percentages are based on figures provided by the 'Handbook of Physical Measurements']. | ||
ADDITIONAL SUGGESTIONS (29-34):
Large 'ridge breadth' (29), hand calluses (30), and possibly brachydactly (31) are a few other aspect that have been confirmed as significant of Fragile X syndrome (which can be understood in the perspective of the relative broad palm shape). The author recognized that some significant hand characteristics for autism - such as: a low AtD angle (32), 'clinodactly' [curved 5th finger] (33), and 'low digit ratio' (34) - can also be expected to be featured with Fragile X syndrome.
And last but not least: Fragile X syndrome is also often featured with rather remarkable hand related behavior such as: hand flapping and hand biting.
SOURCES:
1) Dermatoglyphic peculiarities in families with X-linked mental retardation and fragile site Xq27: a collaborative study. A. Rodewald et al., 1986
2) Dermatoglyphic findings in patients with fragile X-chromosome. L. Hirth, et al., 1985
3) Dermatoglyphic indices of males with the fragile syndrome and of the female heterozygotes. N.E. Simpson, 1986
4) Fragile-X syndrome III: Dermatoglyphic studies in males. N.E. Simpson et al., 1984
5) A dermatoglyphic study of a group of sicilian children with fragile-x syndrome. G. Milone et al., 1988
6) Discriminant analysis of dermatoglyphic measurements in fragile X males and females. D.Z. Loesch, 1988
7) Fragile X syndrome. Molecular and clinical insights and treatment issues. R.J. Hagerman, 1997
in hand diagnostics for fragile-X syndrome?
It is important to notice here that not all hand characteristics are equally significant for recognizing fragile-X 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 fragile-X patients and the control groups.
The following eleven hand characteristics have frequently shown a 10-times higher prevalence percentage in fragile-X groups (compared to the control group): no.1, no.2, no.3, no.9, no.10, no.11, no.12, no.14, no.17, no.25, no.26. So, these hand characteristics belong to the most 'significant' hand features for fragile-X syndrome!
The simian crease (1) is included, but the combination of: the broad, short palm shape; plus the fingerprints on the middle finger (and index finger); plus the progression of palmar line A and line C are probably the most the most significant hand zones to focuss on for recognizing fragile-X 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 fragile-X syndrome.
For people who have the simian line in one hand (or both hands), one can determine the significance for fragile-X 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 fragile-X syndrome:
- (1) mulitiple characteristics from dimension B (hand dermatoglyphics no.3 to no.24: combinations of both palm- and finger characteristics are required),
- (2) plus multiple characteristics from dimenion C (hand morphology no.25 to no.28: combinations of both palm- and finger characteristics are required),
So, if those people have a simian line in hand, 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 fragile-X syndrome!!!
Estimate: those people have a statistical chance of about 95% that a chromosomal test [= genetic testing] will reveal that they have 'fra(Xq27)'! (= the genetic disorder which is responsible for the manifestation of fragile-X syndrome).
FINAL NOTIFICATION:
Below is an illustrative case - including high-resolution handprints - of a woman who has fragile-X syndrome.
Fragile-X syndrome case 1:
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What is in 2010 the state of knowledge about simian lines? ...more.