# Hand A by panniuniu

VIEWS: 15 PAGES: 11

• pg 1
```									A comparison of asymmetry
between monozygotic and
dizygotic twins and siblings

By: Lisa and Laurie DiMente
After reading “Genetic variance in the pattern of the growth
curve for height: A longitudinal analysis of male twins”, and
“A serial study of normal facial asymmetry in monozygotic
twins”, we became interested in the asymmetry of twins,
compared to the asymmetry of siblings.

We were intrigued by this subject because the
article about height said that there was more
symmetry in monozygotic twins then any other
sibling pair. Yet the article on facial Asymmetry
said that asymmetry was not related to twin
zygosity.
 These differences in the journal articles led
us to wonder if asymmetry in hands and
feet of siblings could be related to zygosity.
Hypothesis
 What we expected from this experiment
was that twin pairs especially monozygotic
twin would have a lower difference of
asymmetry than normal sibling pairs.
Methods
2            Using metric ruler take
measurement of fingers 1-
5 from tip of finger to
bottom crease of finger.
1                Then take measurement
from tip of finger 3 to
measure point in diagram.
3 4 5
   Repeat this on both hands
and feet.
Measure point      Record measurements
Equations used to figure out
differences of asymmetry
   X= fingers of right hand and hand measurements
   Y= fingers of left hand and hand measurements
   for each finger and hand | X-Y | = Z
   Sum of all Z / 6 = S (hands)
   Do the same equation to get Sí(foot)
   [S (hands)+S (feet)] / 2= P
   P is the total asymmetry of the person
   Then find the difference between siblings by subtracting the total
asymmetry of each person
Sibling differences (Table 1.)

Dizygotic twins     .15
Monozygotic twins   .0333
Dizygotic twins     .35
Sibling pair a      .1176
Sibling pair b      .0917
Sibling pair c      .025
Sibling pair d      .1083
Sibling differences cont. Table 1

Sibling pair e   .0000000000000004
Sibling pair f   .1417
Sibling pair g   .0667
Sibling pair h   .2667
Sibling pair i   .1167
The data presented in table 1. shows that there are no
trends related to zygosity and asymetery.

Though there are no trends in the results it
must be understood that it could be due to
an extreamly small sample size. If one
wanted to repeat this experiment it would
be beneficial to have a larger sample.
From the data obtained our origional hypothesis
must be rejected, though the results may vary if a
larger sample size was to be used. As shown from
table 1. the smallest amount of difference in
assymetery was found in siblying pair e

and not in a twin pair as we hypothosised.
As stated in ìA serial study of normal facial
asymmetry in monozygotic twinsî our
findings support that asymmetry could not
be related to twin zygosity.
LITERATURE CITED
   Bergman, P.,Belicki, T.,Hauspie, R.C. and, Susanne, C.
1994. Genetic Variation in the pattern of the growth curve
for height: A longitudinal analysis of male twins. Annals
of Human Biology, vol. 21, no.4:347-362.
   Burke, P.H. and Healy, M.J.R. 1993. A serial study of
normal facial asymetery in monozygotic twins. Annals of
Human Biology, vol. 20, no. 6: 527-534.
   (For information about raw data contact Laurie DiMente at
Spring79@juno.com or Lisa DiMente at
Dimente@juno.com)

```
To top