ChromosOmics - Database
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                                                     - CHROMOSOME  21  -                                                   


Heterochromatic

- centromeric
- other heterochromatic variants
Euchromatic

- euchromatic deletions
- euchromatic duplications
References


Heterochromatic - (peri)centromeric variants
for further NOR-region variants principally possible but not specified for13-15 or 21-22 yet see acro-chrs.

case no.
(molecular) cytogenetic result
clinical symptoms
reference
21-
p13-p12/
1-1 to several

dup(21)(p13p12)
none
{1, page 42}
21-
p13-q11/
1-1 to 1-2

dup(21)(p13q11)
none
{1; 6; 7}
21-
p13-q11/
1-3

dup(21)(p13q11)
none
{1; Color Plate 1, VIII)
21-
p13+/
1-1 to several

der(21)(p13amp)
none
{1}
21-
p13-/
1-1 to few

del(21)(p13) or del(21)(p13p13)
none
{1, pages 51-52}
21-
p12+/
1-1 to few

der(21)(p12amp)
NOR

none
{1}
21-
p12-/
1-1 to few

del(21)(p12)
formerly called 'Christchurch-chr.'
or del(21)(p12p12)

none
{1, pages 51-52}
21-
p11.2+/
1-1 to few

der(21)(p11.2amp)
none
{0}
21-
p11.2-/
1-1 to few

del(21)(p11.2) or del(21)(p11.2p11.2)
none
{1, pages 51-52}
21-
cen+/

1-1 to many
21cen+
D21Z1
present in 13% of general population

none
{1, pages 77-78}
21-
cen-/
1-1 to many

21cen-
D21Z1
present in 3.7% of general population as complete absence of signal
20% of chr. 21 have cen-

none
{1, pages 77-78}

Heterochromatic - other heterochromatic variants

case no.
(molecular) cytogenetic result
clinical symptoms
reference
21-
HHM-
own cep/
1-1 to many

D31Z1 = D21Z1 gives always signals 13p11.1q11
none
{1, color plate 1, VIIIb)
21-
HHM-
own cep/
2-1

D13Z1/D21Z1 was inserted in / translocated to 14; 15; 22
none
{1 page 81; 8, 48-54}
21-
HHM-
own p-arm/
1-1

der(21)(pter→p10::p11.2→qter)
none
{1, color plate 1, VIIIb)
21-
HHM-
15p11.2/
1-1 to multiple

der(21)t(15;21)(p11.1;p11.1)
D15Z1 signal on one #21

none
{4; 1, page 46}
21-
HHM-
15p11.2/
2-1

der(21)(15pter→15q11.1:
:15p13→15q11.1:
:21p13→21qter)

none
{1; 9}
21-
HHM-
acro/

1-1 to 1-3
der(21)t(21;acro)(q22.3;p11.2)
none
{0; 1; 98 (case 21qs)}
21-
HHM-
Yq12/
1-1 to 1-2

der(21)t(Y;21)(q12;p11.2) in 2/23 = 7% of cases with t(Y;acro)
none
{3; 1, page 47}

Euchromatic deletions

case no.
(molecular) cytogenetic result
clinical symptoms
reference
21-
EHM-del
pterq21.2/
1-1

del(21)(pterq21.2)
mild to moderate
{1}
21-
EHM-del
q11q21.3/
1-1

del(21)(q11q21.3)
none
{1}
21-
EHM-del
q21.1qter/

1-1
del(21)(q21.1)
none
{1}
21-
EHM-del
q22.3qter/
1-1 to few

del(21)(q22.3)
none
{1; 77}
21-
EHM-del
q22.3qter/
2-1

del(21)(q22.3)
aCGH break in 44.722963 Mb
none
{0 - 44619}

Euchromatic duplications

case no.
(molecular) cytogenetic result
clinical symptoms
reference
21-
EHM-dup
pterq21.1/
1-1 to few

sSMC(21)
none
{sSMC
page}

21-
EHM-dup
q11.2~21.1q21.2/
1-1

dup(21)(q11.2~21.1q21.2)
none
{0 - 27655}
21-
EHM-dup
q13.3q22/
1-1

dup(21)(q22q13.3)
mild to moderate
{1}
21-
EHM-dup
q22.3qter/
1-1 to 1-3

dup(21)(q22.3qter)
due to unbal. t(19;21)
or unbal. t(21;22)

none
{0- 42481; 67}