Tew.
tem
Valle Jt
Frequencyof Sabacitution of boleucine for Other Aasine Acie
in Manian Hemenobin Fro 25 Muarsdalloe
Subject Nu. and sox
3M
1M
Age ut
exposure, 90
24
Vs
JF
I
whe
uy
+r
21
149,74
Iti
hE
“
4a
4s
Me
A
wf!
nw
toSf
t
i
Os40ig
44M
or
J
ay
ob
at
Pixpaosead, ot KR
EF
REF
Cnexpaned
UES MM
Wu
7
wis MM
Vv
ava
we
:
bed
a
nt
“”
i
2
2417
HAG F
4
HioF
tea? F
at
241
MF
dis
al
212
ae
mai F
4a)
71%
Phau Nf
Aoslight, but insignificant, increase inthe ise
keucine substitution frequency was found in cous
trols aged beqween 2Uand 31, the linear regression
has a punitive slope of 0.025} 107%/ year. Except
for subject No. 1547, the higher frequencies were
found in samples from exposed persons, but soure
of the exposed bad values in the contral range
(Table 21). Vhe higher frequencies were observed
more often in individuals exposed at younger ages,
although the globin from subjoot Now 35, exposed
atl veur. had a towisoleucine content. The find-
ings are consistent with the higher leukemia ine
duction, among persous exposed tos rays?and to
atom bamb irradiation”! in these exposed pre:
natally and at voung ages.
Studies in progress stronuly suggest that the in-
creased isoleucine content in the hemoglobin of
exposed Marshallese is duc to base-substitution
somatic mutations, The supporting data™ include
analyses showing (1) that higher isalcucine sulat-
4
:
abs be
:
.
'
aon
At
Jo
41
Ei M
]
i
4
it
:
om
ld F
BM
HUF
'
'
14.4%
!
2
Averave +
SEM (x 10-4)
Jc
:
42 F
:
Substitution
frixqucmey (xX 14)
MD
2UF
Aye at
prencnt, ve
RS ES
Rn
ieee nme ge i
|
Sb
4
'
$47
Ss
Lash
hl
ba}
Lt
tution fequencies occur in both the alpha and
beta chains of hemoulobits froin exprscad persons,
und (2) that conluniaation by fetal beaogalina,
Shick does contain bobeuciue, could contribute oo
there thaw ¢ parts por milion amino acid residues
to the values reported ia Table 20.
J. Genetic Studies
@. Possible Radiation Effects. ‘Uhe inheritame
of cadiagon-indueed mutations has bees amply
demonstrated ia wenche studies on aiiaals, bat it
has at been unequivocally scen in aman. Large
numbers of animals are accessary te demonstrate
such anel feet. and the size of the irradiated lannan
populations studied is probably too small for it te
le readily detected. “The largestescale human
Mudy was made by Neel et al. onthe children of
parcats exposed in Hiroshima and Nagasaki"!
aud it slowed no cle-ecul geactic cllects. Exam.
nations of the much smaller group of Marshallese
s
: