ChromosOmics - Database
tl_files/tiny_templates/Bilder
                          TL/sSMC-book.jpg tl_files/tiny_templates/Bilder
                          TL/hetmorh-book.jpg

                                                  CHROMOSOME #21 -                                                 
NEOCENTRIC
 
Cases without clinical findings
Similar imbalances – no sSMC
Cases with clinical findings
Similar imbalances – no sSMC
Cases without clear clinical correlation
Cases with discontinous sSMC
Cases with complex sSMC
Cases with UPD and sSMC
Cases with neocentromeres
Similar imbalances - no sSMC
Tumor
DISCLAIMER
In general 70% of sSMC carriers are clinically normal. The figures listed above

are based on the bias, that mainly clinically aberrant cases are studied and reported in literature!


UPD (uniparental disomy) cases: UPD(21)mat UPD(21)pat UPD(21)mat or pat

Cases with neocentromeres (N)

case no.
gender/
age at diagnosis

studied
material

de novo/
inherited

GTG-banding result
grade of mosaicism

final result of the sSMC
test
methods

clinical symptoms
Reference
21-
N-
p or q/
1-1
-
-
-
-
-
-
-
-



1 neocentromere 21 case (no sSMC):
Barbi G, Kennerknecht I, Wohr G, Avramopoulos D, Karadima G, Petersen MB.
Mirror-symmetric duplicated chromosome 21q with minor proximal deletion, and with neocentromere in a child without the classical Down syndrome phenotype.
Am J Med Genet. 2000 Mar 13;91(2):116-122.

Cases with neocentromeres (N) - TUMOR

case no.
gender/
age at diagnosis

studied
material

de novo/
inherited

GTG-banding result
grade of mosaicism

final result of the sSMC
test
methods

clinical symptoms
Reference
21-
N-
p or q/
1-1
-
-
-
-
-
-
-
-

N-Cases with similar imbalances NOT caused by sSMC (N-IMB):

case no.
gender/
age at diagnosis

studied
material

de novo/
inherited

GTG-banding and final FISH result test
methods

clinical symptoms
Reference
21-
N-

IMB-
p10/
1-1
male/
newborn
PBL de novo 47,XX,+inv dup(21)(p11.1) wcp 12, 21 neonate revealed similarities to Down syndrome {20}
21-
N-

IMB-
p10/
1-2
see above - similar case {23} case 17
21-
N-

IMB-
p10/
1-3
see above - similar case {30} case 23
21-
N-

IMB-
qter/
1-1 to
mult
see {28} {28}
-
-
-
-
-
-
-
-