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

                                                  CHROMOSOME #21 -                                                 
UNCLEAR
 
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 unclear clinical correlation (U)

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-
U-
1
female/
prenatal
CH de novo 47,XX,+mar[9]/
46,XX[6]
min(21)
in later performed amniocentesis 47,XX,+21
different FISH probes:
D13/21Z1
CVS due to advanced fetal nuchal translucency of 7.6 mm.
Down-syndrome
{3} case 1
21-
U-
2
see 21-Uc-2
21-
U-
3
male/
prenatal
AF de novo 47,XY,+r[32]/
46,XY[18]
r(21)(::p10q22.?::)* all available centromeric probes; wcp 21 Amniocentesis due to raised serum screen risk; TOP {6} case 25
21-
U-
4
male/
prenatal
AF/fetal tissue de novo 47,XY,+21[25]/
47,XY,+mar[34]/
46,XY[41]
min(21) (wcp21+,cep13/21+)
cep 13/21; wcp21
AMA, TOP as Down-syndrome mosaic symptoms were expected; post-mortem examination did not show any abnormalities {9}
21-
U-
5
male/
prenatal
AF de novo 47,XY,+mar[100%] min(21)(:p11.2q11.2:)[1]/
inv dup(:p11.1
q11.2:
:q11.2
p11.1:)[1]/
dic(21)(:q11.2
p11.1:
:q11.2
p11.1:)[3]/
dic(21)(:p11.1
q11.1:
:p11.1
q11.2:)[2]

cenM/
subcenM
Prenatal diagnosis. Indication was a previous pregnancy with triploidy. No echographic indication and no follow-up available {0} provided by Dr. J. Vermeesch, Leuven, Belgium
21-
U-
6
see mult 2-21
21-
U-
7
see 21-Uc-3
21-
U-
8
male/
prenatal
AF de novo 47,XY,+mar[100%] min(21)(pter→q21.1:)*
distal marker on sSMC RP11-143A3 (18.24 MB)
aCGH FISH abnormal ultrasound findings and AMA; child born; no info available {18} case 3
{29}case 5
21-
U-
9
female/
prenatal
AF de novo 47,XX,+mar[50%]/
46,XX[50%]
min(21)(pter→q11.2~21.1:) cenM; subcenM; LSI 21 AMA; plexus cysts; TOP; in autopsy normal apart from hypertelorism {0} provided by Dr. Altus, Magdeburg, Germany
21-
U-
10
female/
13y
PBL n.a. 47,XX,+mar[8]/
46,XX[22]
min(21)(pterq11.2~21.1:) cep probes; subcenM; LSI 21 n.a. {0} provided by Dr. Prager/ Junge, Dresden, Germany
21-
U-
11
female/
prenatal
AF/PBL de novo 47,XX,del(21(q22),+mar[22]/
46,XX,del(21)(q22)[7]/
46,XX,-21,+mar[5]/
45,XX,-21[4]
min(21)(pterq11.2:) FISH with LSI 21 and AML1; aCGH see below {31}
AMA; at birth lenght 46 cm (-2.74 SD), weight 2240 g (-4.4 SD), head circumference 31 cm (-3.16 SD). APGAR scores 1/8/9. High nasal root, downslanting palpebral fissures, retrogenia, posterior rotated, slightly low-set ears, a long philtrum, and a thin upper vermillion were noticed. The fingernails were small. A sacral dimple was observed. Cerebral ultrasound showed a missing septum pellucidum. Major problem was feeding, most probably due to sucking weakness and a lack of coordination so that a feeding tube had to be placed.
21-
U-
12
female/
prenatal
AF de novo 47,XX,+mar[13]/
46,XX[6]
min(21)(pterq11.2~21:) cenM, subcenM, LSI 21 (not on sSMC) AMA; lost during follow-up {0} provided by Dr. Schliephagen, Linden, Germany
21-
U-
13
female/
11y
PBL n.a. 47,XX,+r[100%] r(21) SKY dermatitis, acquired acanthosis nigricans {36} case F067630
21-
U-
14
female/
prenatal
AF n.a. 47,XX,+mar[100%] min(21)(pterq11.2:) cenM, subcenM AMA {0} provided by Dr. Wegner, Berlin, Germany
21-
U-
15
see 21-Uc-4
21-
U-
16
see 21-Uc-5
21-
U-
17
female/
prenatal
AF n.a. 47,XX,+mar[100%] mar(21)(:q11.2→q21.1:) arr[hg19]15.48-21.70 Mb aCGH n.a. {0} provided from Portugal
21-
U-
18
male/
prenatal
AF n.a. 47,XY,+mar[60%]/
46,XY[40%]
del(21)(q11.2) or min(21)(:p11.2→q11.2) cenM;
subcenM
AMA {0} provided by Dr. Bartels, Göttingen, Germany
21-
U-
19
n.a./
prenatal
AF n.a. 47,XN,+21[5%]/
47,XN,+mar[10%]/
46,XN[85%]
min(21)(:p11.1→q22.13:) cenM;
subcenM
AMA {0} provided from Portugal
21-
U-
20
female/
prenatal
AF/ CH de novo 47,XX,+mar[18]/
46,XX[4]
del(21)(q21.1)
aCGH: break in 18.34 Mb (hg18 or 19?)
SKY, aCGH AMA; normal sonography, normal in autopsy
TOP
{43}
21-
U-
21
female/
prenatal
AF
de novo 47,XX,+mar[100%] min(21)(pterq11.2:) ceps, BACs and MLPA AMA; normal sonography, TOP {32}
21-
U-
22
n.a./
prenatal
AF
n.a. 47,XN,+mar[4]/
46,XN[66]
inv dup(21)(pterq21.1:
:q21.1
pter)
arr[GRCh37] 21q11.2q21.1(15901076_
20655419)x3 (30%)
aCGH, subcenM
AMA {0} provided from Portugal
21-
U-
23
n.a./
prenatal
placenta
mat 47,XN,+mar mar(21)(pterq21.1:) NIPT
n.a.; mother normal (mosaic?)
{56} case 3
21-
U-
24
male/
prenatal
AF
de novo
47,XY,+mar[32]/
46,XY[68]
inv dup(21)(q11.2) NIPT
AMA, songraphy normal
{0} provided from Serbia

Cases with complex sSMC (Uc)

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-
Uc-
1
n.a./
n.a.
PBL n.a. 46,tROB(21;22),mar[100%] der(21)t(21;22)(q11.1;p11.2)* centromeric probes for 13/21 and 14/22 normal {1} case 2
21-
Uc-
2
male/
2.5y
PBL familial
maternal t(17;21)(p?;q?)
47,XY,+mar[100%] most likely
t(17;21)(p?;q?)
n.a. severe growth and MR {4}
21-
Uc-
3

male/
12y
PBL maternal t(7;21) 47,XY,+mar[100%] der(21)t(7; 21)(p21;q21.3) FISH different probes acc to {17} see below {17; 39}
Born at term after normal pregnancy. Birth weight 4010 g, length 50 cm head circumference 35 cm. Pneumonia and septicemia complicated the neonatal period. At 4 months infantile spasm. Encephalographic investigations showed hypsarrhythmia. Two hypopigmented spots on the skin, positive to Wood's light, aroused suspicion of tuberous sclerosis. Computerized tomography of the brain showed mild to moderate central and cortical atrophy. On this basis, tuberous sclerosis was excluded as a possible diagnosis. Repeated upper respiratory tract infections and otitis, suffered from constipation, and severe feeding problems. Psychomotor development severely retarded. He sat without support first at 14 months and was not able to walk until age 6 years and 6 months. At 12y unable to speak or to use sign language. He is autistic, which was obvious already before the age of 1 year. At 8 years - height 111 cm (<-3 S.D.), weight 20 kg (-2 S.D.) and head circumference 51.5 cm. (+0 S.D.). He did not resemble the other members of his family. He had a prominent forehead, down slanted palpebral fissures and hypertelorism. Strabismus was noted and he had mild hyperopia. He had a high and broad nasal bridge, a broad nose, a prominent philtrum, a large mouth, prominent lips and down-turned corners of the mouth. The palate was short and narrow. He had micrognathia, prognathism, low-set, dysplastic and posteriorly rotated ears and narrow ear canals. He had mild muscular hypotonia, hyperextensibility of joints, pes calcaneo-valgus, brachydacyly and single transverse palmar crease unilaterally.
21-
Uc-
4
female/
2 y
PBL maternal
t(4;21)
47,XX,+mar[100%] der(21)t(4;21)(q32.1;q21.2) aCGH MR, DD, facial abnormal {39; 47}
21-
Uc-
5
n.a./
prenatal
AF maternal
t(4;21)
47,XN,+mar[100%] der(21)t(4;21)(q35.2;q11.2) aCGH n.a. {41}
21-
Uc-
6
female/
8 y
PBL maternal
t(4;21)
47,XX,+mar[100%] der(21)t(4;21)
(q25;
q22.13~22.2)
FISH MR, DD, facial abnormal {48}
21-
Uc-
7
female/
3y
PBL maternal
t(4;21)
47,XX,+mar[100%] der(21)t(4;21)(q24;q21) FISH MR, DD, facial abnormal {49}
21-
Uc-
8
n.a./
n.a.
n.a. maternal
t(4;21)
47,XN,+mar[100%] der(21)t(4;21)(q32;q22.2) n.a. n.a. {50}
21-
Uc-
9
female/
7 y
PBL maternal
t(4;21)
47,XX,+mar[100%] der(21)t(4;21)(q27;q21) n,a. MR, DD, facial abnormal {51}
21-
Uc-
10
female/
2 y
PBL maternal
t(4;21)
47,XX,+mar[100%] der(21)t(4;21)(q21;q21) n.a. MR, DD, facial abnormal {52}
21-
Uc-
11
male/
4 y
PBL n.a. 47,XY,+mar[100%] der(21)t(20;21)(q13.2;q22.12) aCGH MR, DD, facial abnormal; autism {0}
21-
Uc-
12
female/
 
postnatal
PBL familial
t(9;21)
47,XX,+mar[100%] der(21)t(9;21)(p24;q21.4) n.a.
MR, DD {53}
21-
Uc-
13
male/
20 y
PBL maternal
t(10;21)
47,XY,+mar[100%] der(21)t(10;21)(q26;q22) n.a. MR, DD, DYS {54}
21-
Uc-
14
female/
  11 y
PBL paternal
t(4;21) with inv(4)(p14q21.3)
47,XX,+mar[100%] der(21)t(4;21)(q32.3;q21.3) aCGH MR, DD, DYS {57}
21-
Uc-
15
2 sibs/
 
postnatal
PBL parental
t(4;21)
47,XN,+mar[100%] der(21)t(4;21)(q31.3;q11.2) n.a. mild MR, DD {59}
21-
Uc-
16
n.a./
 
postnatal
PBL maternal
t(16;21)
47,XN,+mar[100%] der(21)t(16;21)(q11;p11) n.a. MR, DD {60}


Cases with discontinous sSMC (Ud)

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-
Ud-
1

female/
newborn
PBL de novo 47,XX,+mar[100%] r(21)(::p11.1q11.2:
:q21.3
q22.11::)
array-data: (~12)-15.70MB and 29.28 - 31.12 MB
cep 13/21 BACs see below {33}
Birth weight 2,370g, Apgar score 7 at 1 min; mild facial dysmorphisms and hypotonia. At 2 months seizures; weight 5,250 g (90th to 97th centile), length 55 cm (25th to 50th centile), general muscular hypotonia, malformed ears, umbilical hernia, gastroesophageal reflux, but neuropsychiatric evaluation, EEG, and MRI of the brain normal; at 5 months weight 11,700 g (>97th centile); later slight delay in psychomotor development, especially speech delay; sitting without support at 7 months, walk without support at 20 months.
21-
Ud-
2
male/
2y
PBL de novo 47,XY,+mar[100%] der(21)(pterq12:
:q21.2
q21.3:)
aCGH: 21p11q21.1
(10,827,533-20,813,004)x3,
21q21.2q21.3
(25,913,510-30,831,133)x3
cep; subcenM;
aCGH
DD - suggested for PWS {0} provided by Jasen Anderson, Brisbane, Australia

Cases with UPD (Uu)

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-
Uu-
1
-
-
-
-
-
-
-
-