Somatic hypermutations usually occur by transitions or transversions. However, a few examples of rearranged IGHV genes have been described in which somatic hypermutations correspond to insertions or deletions in the CDR-IMGT, or exceptionally in the FR-IMGT. These examples are reported and analysed in this table.
| Antibody name
|
Antibody specificity
|
Rearranged IGH V-D-J-REGIONs
|
IMGT reference sequence of the corresponding germline V-REGIONs (2) |
Description of mutations by deletions/insertions
compared to the germline V-REGIONs |
Accession
numbers |
CDR-IMGT length (1) |
IGHV gene and allele name |
Accession numbers |
CDR-IMGT length |
ITC33
(IgG1)
[1] [7] |
CMV gB
Cytomegalovirus glycoprotein B |
L26531 |
[11.8.14] #c |
5-51*01 |
M99686 |
[8.8.2] |
78^79>ins^gcagacggt
26^27>ins^ADG |
The 3 additional amino acids A (Ala), D (Asp) and G (Gly) are localised
at the beginning of the CDR1-IMGT loop. Their position numbers are 26A,
26B and 26C, respectively. |
71-31
[7] |
HIV-1 p 24 |
M67502 |
[8.7.12] #c |
1-46*01 (3) |
X92343 |
[8.8.2] |
a184-c186>del(3nt)
S62>del(1AA) |
The deleted amino acid S62 corresponds to a position at the end of
the CDR2-IMGT loop. |
K14
(IgG1, k)
[4] [7] |
HIV-1 gp 41 |
|
[8.9.13] #c |
3-23*01 |
M99660 |
[8.8.2] |
168^169>ins^att
56^57>ins^I |
The additional codon att encoding isoleucine at position 56A is a duplication of codon 56 (att). The additional Ileu is localised at the beginning of
the CDR2-IMGT loop. |
HBp2
(IgM)
[2] [7] |
Bordetella pertussis
lipooligosaccharide |
L21957 |
[11.9.10] #c |
6-1*01 |
X92224/
J04097 |
[10.9.2] |
96^97>ins^agc
32^33>ins^S |
The additional codon agc encoding serine at position 32A is a duplication
of codon 32 (agc). The additional Ser is localised at the top of the CDR1-IMGT
loop. |
| Antibody name
|
Rearranged IGH V-D-J-REGIONs |
IMGT reference sequence of the corresponding germline V-REGIONs (2) |
Description of the mutations by
deletions/insertions
compared to the germline V-REGIONs
|
Accession
numbers |
CDR-IMGT length (2) |
IGHV
gene and allele name
|
Accession
numbers |
CDR-IMGT
length |
ST
(IgG)
[6] |
X94075 |
[8.11.14] #c |
5-a*03 |
X56375 |
[8.8.2] |
177^178>ins^gatcctaat
59^60>ins^DPN |
The 3 additional amino acids D (Asp), P (Pro), N (Asn) are localised
at the tip of the CDR2-IMGT loop. Their position numbers are 59A, 59B and
59C, respectively. |
BF2P2-g3C01
[3] |
Z80499 |
[8.9.12] #c |
3-23*01 |
M99660 |
[8.8.2] |
168^169>ins^acc
56^57>ins^T |
The additional amino acid T (Thr) is localised at the beginning of
the CDR2-IMGT loop. Its position number is 56A. |
3D15VH3
[3] |
X73172 |
[8.X.X] #c |
3-23*01 | M99660 |
[8.8.2] |
g123-a172>del(50nt)#
W41-S57>del(17AA)# |
The deletion of 50 nucleotides leads to a frameshift and encompasses
the FR2-IMGT and the CDR2-IMGT. |
tm121
(IgM)
[8] |
AF013615 |
[10.9.X] #c |
6-1*01 |
X92224/J04097 |
[10.9.2] |
255^256>ins^aagaac
85^86>ins^KN |
The 2 additional amino acids K (Lys) and N (Asn) are localised in the
middle of the FR3-IMGT. Their position numbers are 85A and 85B, respectively. |
| [8] |
AF013616 |
[16.7.19] #c |
4-31*03 (4) |
Z14237 |
[10.7.2] |
87^88>ins^ttcacctctggtgactcc
29^30>ins^FTSGDS |
The 6 additional amino acids F (Phe), T(Thr), S (Ser), G (Gly), D (Asp)
and S (Ser) are localised at the beginning of the CDR1-IMGT loop. Their
corresponding numbers are 29A, 29B, 29C, 29D, 29E and 29F, respectively. |
| [8] |
AF013617 |
[6.7.19] |
4-34*01 |
X92278 |
[8.7.2] |
t97-c102>del(6nt,tactac)
Y33-Y34>del(2AA)
|
The deleted amino acids Y33 and Y34 correspond to positions at the end of the CDR1-IMGT loop.
|
| [8] |
AF013619 |
[11.7.16] #c |
4-39*01 |
L10094 |
[10.7.2] |
102^103>ins^wac
34^35>ins^N/Y
w: a or t
wac: N (Asn) or Y (Tyr) |
The additional amino acid is localised at the end of the CDR1-IMGT
loop. Its position number is 34A. |
