ChromosOmics - Database

Icon by Leon Liehr                   

                                                  CHROMOSOME #20 -                                                 
ABNORMAL

Cases without clinical findings
Similar imbalances – no sSMC
Cases with clinical findings
Similar imbalances – no sSMC
sSMC – not well characterized
Cases with isochromosome 20p
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

References

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(20)mat UPD(20)pat UPD(20)mat or pat

Cases with clinical findings (W)

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
20-
W-

p13/
1-1
male/
8m
PBL de novo 47,XY,+r[60%]/
46,XY[40%]
(at 3y 65/100 cells in PBL with mar; in buccal mucosa 3 signals with cep 20 in 18% of cells)
r(20)(::p13q1?2::)* all centromeric; telomeric, and probe in 20p12-13 see below {10}
Uncomplicated pregnancy; weight: 4250g, length: 52cm; umbilical hernia one unilateral hydrocele and restricted mobility of hips; at 8m developmental delay and dysmorphic features like full cheeks, deep-set eyes, slight upslanting palpebral fissures, convergent strabismus of left eye; lipoma at base of nose at age of 14m; mild micrognathia, broad neck and thorax, diastasis recti, clinodactyly of 5th fingers; walking at 23m;
20-
W-

p13/
2-1
see 20-W-iso/1-4
20-
W-
p13/
2-2
female/
prenatal
AF n.a. 47,XX,+mar[29]/
46,XX[19]
mar(20)(pterq11.1)
could also be an iso chromosome
aCGH: 2.97-32,13 MB
aCGH sonographic findings - TOP: DYS, thumb anomalies,
agenesis of pancreas tail, bicornate uterus
{57} case 24
20-
W-

p13/
3-1
see 20-U-9
20-
W-

p13/
3-2
n.a./
prenatal
AF de novo 47,+mar min(20)(pterq10:) n.a. ultrasound abnormalities, TOP {44} 1 case
20-
W-

p13/
4-1
see 20-N-pt11.2/1-1
20-
W-

p13/
5-1 = 5-2

see 20-W-iso/1-2
20-
W-
p12~13/
1-1
male/
postnatal
PBL n.a. 47,XY,+mar[26]/
46,XY[4]
r(20)(::q11.1→p12~13::)[7]/
r(20)(::q11.1→p12~13:
:q11.1→p12~13::)[1]/
min(20)(:q11.1→p12~13:)[1]/
min(20→q11.1:
:q11.1→p12~13:)[1]
cenM
pcp 20p, 20q
subtel 20p and 20q
facial DYS , cleft palate, DD {0} provided from Ecuador
20-
W-
p12.3/
1-1
female/
8y
PBL n.a. 47,XX,+mar[18]/
46,XX[12]
min(20)(:p12.3q11.22:) NGS Dwarphism
{67} case 70963
20-
W-
p12.1/
1-1
female/
prenatal
AF de novo 47,XX,+mar[100%] mar(20)(p12.1→q13.13)
aCGH (hg18): 15,803,492-47,986,155
aCGH see below {0} provided by family
Born via C-section at 40 weeks due to breech presentation. At birth cyanotic and floppy with left positional torticollis. DYS: anteverted nostrils, epicanthal folds, high arched palate. Also sloped shoulders, and pectoral muscles smaller than normal. Cardiology followed for 5 years due to a combination of a slight heart murmur when she was born (resolved), a slight twisting of the descending aorta; at 5y no heart problems detected. At 3y strabismus in her left eye and moderate pronation. Also in first years susceptibility to respiratory infections, and developed obstructive sleep apnea. At 5y height ~75th percentile, weight ~80-85th percentiles and mild eczema. Gross motor milestones were delayed; at 6y able to walk, run, and jump.Still severe language disorder, and moderate-severe receptive language disorder with major articulation difficulties. Poor fine motor skills; suggested to have dyspraxia. Diagnosed as ‘untypical autistic’, and a school system test diagnosed her as having an IQ of 76
20-
W-

p11.2/
1-1

°°°
female/
1m (?)
PBL
fibroblast
de novo 47,XX,+r[67%]/
46,XX[33%]
47,XX,+r[83%]/

46,XX[12%]
r(20)(::p11.2q10::) midi; UPD-test see below {5} case N
born during pregnancy week 38 with growth retardation, weight 1,940 g, length 45 cm; marked feeding problems, poor weight gain, no malformations other than a small ASD. At 30 m she developed normally, but she was still very small and had feeding difficulties.
20-
W-

p11.23/
1-1
female/
prenatal
AF de novo 47,XX,+mar[54%]/
46,XX[46%]
r(20)(::p11.23q11.22::)
FISH-data: RP5-1096J16 in 20p (20.19MB) to RP11-353C18 in 20q (33.83MB)
M-FISH;
BACs
see below {46} case 1
Amniocentesis due to intrauterine growth retardation (week 22); TOP at 34 weeks; weight was 1,630 g (5th centile), height 43 cm (10th centile), and occipitofrontal circumference (OFC) 27.5 cm ([lt]5th centile). Moderate craniofacial dysmorphism, including elongated skull with a shelf, a broad nose, a bilateral crease below the lower eyelids, microretrognatia, normally implanted but abnormal ears, and a slight nuchal edema. Hands, feet, and genitalia were normal. Internal examination showed no anomaly. Skeletal X-rays were normal.
20-
W-

p11.22/
1-1
female/
1.5 y
PBL n.a. 47,XX,+mar[18]/
46,XX[9]
min(20)(:p11.22~11.21
q11.21:)
FISH: 25.47 and 29.92
aCGH: 24.70-25.70
centromeric probes; subcenM;
aCGH
DD, lipoma of the corpus callosum, hypotonia, VSD, ASDII {56} case Sm-10
20-
W-

p11.22/
1-2
female/
4y
PBL
(EKF-
cellbank)
de novo 47,XX,+mar[7]/
46,XX[4]
min(20)(:p11.23→q11.22:) cenM; subcenM;
CR-FISH;
UPD-test
see below {67} case 7
Born after uneventful pregnancy, 38th week of gestation (2850g weight). Long bones were reported as shortened at birth; suggestion of hypochondroplasia, parents also small (~160cm). At 4y: height: 91.8cm ([lt]3 centile), Weight: 15.4 kg (10.-25. centile). Breathing through mouth, speech is slurred, and poor in vocabulary. Macrocephaly, slightly reclined neck, short long bones, strong suborbital skin fold, flat nasal root. Intelligence borderline (60-70).
20-
W-

p11.22/
2-1

°°°
female/
postnatal
PBL de novo 47,XX,+mar[100%] min(20)(:p11.2?2q11.1:) cenM; subcenM DD and facial DYS. Hypotelorism and macrocephaly {0} provided by Dr. J. Vermeesch,
Leuven, Belgium
20-
W-

p11.21/
1-1
male/
8y
PBL n.a. 47,XY,+mar[%?]/
46,XY[%?]
min(20)(:p11.21q11.21:) cenM; subcenM see below {37} case 31
congenital malformations, born at term, heart defect suspected, weight 4010g, length 52cm, at 8y mild motor development delay, muscular hypertonia, dystonia; at 7 years: weight 26 kg, length 127cm, OFC=55cm, macrocephaly (borderline), dolichocephaly, prognathia, large alveolar ridge, brain: dilated lateral ventricles (moderate), low-set dysplastic ears, epicanthus, short wide nose, short philtrum, arched palate; small umbilical hernia, polythelia, short neck, speech dysarthria
20-
W-

p11.21/
2-1
n.a./
postnatal
PBL de novo 47,+mar[75%]/
46[25%]
mar(20)(:p11.21q11.21:)
size 1.9 MB
n.a.; subcenM with 3 BACs, aCGH Psychomotor delay {29} case 22
20-
W-

p11.21/
3-1

°°°
female/
prenatal
AF de novo 47,XX,+mar[12]/
46,XX[10]
r(20)(::p11.21q11.23:)
size 10.8 MB; breaks in positions 24.17MB and 36.44MB
wcp probes; aCGH see below {45}
{57} case 23
Amniocentesis due to a Turner syndrome in previous pregnancy; normal sonography; TOP in week 24; postmortem examination: weight 670g (50th centile); length 32 cm (25th centile); OFC 22.5cm (50t centile), dysmorphism: high forehead with frontal bossing, voluminous ocular globes, hypertelorism, low set ears with hypoplastic helix, wide flat nasal bridge, long smooth philtrum, thin upper lip, microretrognatia, hypoplastic labia and clitoris, rocker bottom feet;
20-
W-

p11.21/
3-2
male/
prenatal
AF de novo 47,XY,+mar[100%] min(20)(::p11.21q11.23:)
  breaks in positions 23.10MB and 34.53MB (hg19)
wcp probes; aCGH enhanced NT; After birth: DYS; smal male gentitalia; heart defect (VSD; PFO), hypotonia, cutis marmorata; DD; growth delay, microcephaly
{68}
20-
W-

p11.21/
4-1
female/
prenatal
AF de novo 47,XX,+mar[40%]/46,XX[60%]
- 47,XX,+20 in chorion
min(20)(:p11.21q11.22:)
aCGH (hg19): 25.4-34.15 Mb
cenM
subcenM UPD-test aCGH
abnormal phenotype {0} provided by Dr. Manolakis, Athens Greece
20-
W-

p11.1/
1-1
female/
prenatal
AF, PBL
(EKF-
cellbank)
de novo 47,XX,+mar[20] min(20)(:p11.1q11.1:) {cenM}
47,XX,+min(20)(:p11.1
q11.23:)[18]/47,XX,+min(20)(:q11.23p11.1::p11.1q11.23:)[7]/
47,XX,+r(20)(::p11.1
q11.23::p11.1q11.23::)[3]/46,XX[2] {subcenM; CR-FISH}
cenM
subcenM
CR-FISH
child born, at age of 2 retardation in speech development; weak ear dysmorphism and slight clinodactyly of 5th finger {2} case 10
{67} case 8
20-
W-

p11.1/
2-1
see 20-U-10
20-
W-

p11.1/
3-1
female/
18y
PBL n.a. 47,XX,+mar[100%] min(20)(:p11.1q11.1:)* different FISH probes, micro satellite analysis; UPD-test see below {12} case 4
Female studied due to primary amenorrhea, hirsutism, mild mental retardation; myopic retinal degeneration, horizontal nystagmus, no uterus and abnormal ostium of urethra in the bladder.
***
20-
W-

p11.1/
4-1

°°°
female/
newborn
AF/
PBL
de novo 47,XX,+mar[100%] min(20)(:p11.1q11.21:)
array (hg19):
29.63-31.35 MB
aCGH; cep 20 see below {0} provided by Dr. L. Rodriguez, AbaCid, Madrid, Spain
Normal pregnancy but with oligoamnios and IUGR since 32th gestational week. At birth weight of 2050 g; OFC: 32 cm, length: 43.5 cm all values (<3. centile) and hypotonic. No gain of weight for 2 months; then an intrathoracic stomach with duodenal bulb infradiaphragmatic, a light colpocephaly and corpus callosum hypoplasia was detected; after surgery good evolution, getting oral alimentation.
20-
W-

p11.1/
4-2

°°°
female/
2m
PBL de novo 47,XX,+mar[100%] min(20)(:p11.1q11.21:) aCGH, FISH see below {33}
birth weight, OFC and lenght >3. centile; intrathoracic stomach with duodenal bulb infradiaphragmatic, a light colpocephaly and corpus callosum hypoplasia were diagnosed. After surgery she is having good evolution, getting oral alimentation and at 4 months old she weights 4110 gr.
20-
W-

p11.1/
5-1

°°°
male/
prenatal
AF and PBL n.a. 47,XY,+mar[100%] min(20)(:p11.1q11.23:)[5]/min(20)(:p11.1q11.23::q11.23p11.1:)[1]
arr hg19: 29.8-37.5 MB
cenM, subcenM, aCGH see below {0} provided by Dr. Zvi Borochowitz; Israel
AMA, at 1 y: sparse scalp hair, high forehead, low set ears, protruding ears, long philtrum, nystagmus, upturned nares, tubular fingers, broad thumbs and toes, clinodactyly of V finger. global MR and DYS
20-
W-

p10/
1-1
see 20-Ud-1
-
-
-
-
-
-
-
-
-

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

case no.
gender/
age at diagnosis

studied
material

de novo/
Inherited

GTG-banding and final FISH result test
methods

clinical symptoms
Reference
20-
W-

IMB-
p12.1/
1-1

°°°
n.a./
n.a.

PBL
de novo 46,dup(20)(p11.2p12.1)/46 n.a. Sotos syndrome (cerebral gigantism) {32}
20-
W-

IMB-
p11.23/
1-1
male and female/
n.a.

PBL
familial 46,dup(20)(p11.21p11.23) n.a. Alagille syndrome (arteriohepatic dysplasia, AHD) without liver involvement {33}
20-
W-

IMB-
q11.1/
1-1

°°°
male/
2m

PBL
de novo 46,XY,dup(20)(q11.1q12)
RP1184++,RP11-382A12++
wcp 20, MCB, BACs facial DYS= prominent metopic suture, epicanthic fold, peripalpebral edema, small and thick ears, prominent cheeks; walking with 25m, speech delay; at 3y no growth abnormalities. {28}
20-
W-

IMB-
q11.2/
1-1

°°°
male/
16m

PBL
male/
16m
46,XY,dup(20)(q11.2q12) wcp 20, BACs psychomotor retardation, craniofacial anomalies and severe vision deficit. {34}

W-cases with unclear/insufficient characterization of the sSMC (CW)

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
20-
CW-
1
male/
2y
PBL de novo 48,XY,+mar x2[28%]/
47,XY,+mar[72%]
r(20) FISH with all available centromeric probes DYS like scaphocephaly, high pitched voice, high palate, clinodactyly of fingers 2, 4 and 5 towards the 3rd finger, short stature {7} case 10
20-
CW-
2
male/
2y8m
PBL de novo 47,XY,+r[25%]/
46,XY[75%]
r(20) FISH with all available wcp probes see below {13}
Normal pregnancy, born in 39th week, weight, length and OFC normal, APGAR 9/9/-; at 2y8m psychomotor retardation, facial abnormalities, brachyturricephaly, normal set ears with lobe crease, high arched palate, short neck, bilateral clinodactyly of 5th finger; both testes in inguinal canal.
20-
CW-
3
male/
prenatal
CH/PBL/
fibroblast
de novo 47,XY,+mar[16-87%]/
46,XY[6-31%]
+20 cell line absent in PBL; mar present in all studied tissues
r(20) (cep20+; wcp20+) different FISH probes: wcp20; cep20 see below {8}
CVS due to advanced maternal age; born at 35 weeks' gestation following preterm prenatal. rupture of membranes. APGAR score 2/6/8; Birth weight 1730 g (10. percentile) length 44.5 cm; Noted at birth: asymmetric, triangular face; prominent forehead; bulbous nose with slightly upturned tip; hypoplastic and short philtrum; small mouth; high palate; micrognathia; retrognathia; large, flat, and simple ears; redundant skin on neck, chin, and upper shoulders; blind shallow sacral dimple; proximally placed thumbs which folded over the palms; clinodactyly of the second, fourth, and fifth fingers; feet held in eversion, prominent heels; wide space between the first and second toes; proximally placed fifth toes; hypotonia; increased skin elasticity; and hyperextensible joints. At 34 m: failure to thrive, dysfunctional swallowing, and generalized hypotonia; gross motor development delayed, but fine motor coordination, expressive language, and problem solving were appropriate for age. On follow-up at 13 months, the patient's weight was 6730 g (5. percentile) and height was 68'5 cm (5. percentile); percutaneous gastrostomy tube for feeding. At 16 m, weight 8230 g (3. percentile); height 70,8 cm (3. percentile) still required gastrostomy tube feedings.
20-
CW-
4
male/
2.5y
PBL de novo 48,XY,+rx2[4%]/
47,XY,+r[71%]/
46,XY[25%]
r(20) (cep20+; wcp20+) FISH with centromeric probes for chrs. 2, 20, Y and wcp 20 see below {9} case 3
{11} case 34
Global DD in gross motor, fine motor, speech and social skills, height and weight below 3rd centile, heart defect, hypertelorism, depressed root of nose, low-set ears, bilateral plantar furrow (1, 2), clubbed fingers
20-
CW-
5
male/
14m
PBL maternal
mother:
47,XX,+r(20)[8]/
46, XX[42]
47,XY,+r(20)[skin 11 - blood 25]/
46, XY[skin 14 - blood 37]
r(20)(cep20+; wcp20+) FISH with wcp 20 see below {26}
At 14 m DD and some dysmorphic features. Born at 39 weeks gestation after uncomplicated pregnancy; at birth small and broad hands and feet as well as low set ears were noted. At 14 months coarse round facies, full cheeks, slight upslanted palpebral fissures, convergent strabismus, micrognathia, high and narrow palate, low set ears, brachycephaly, broad neck and chest, pectus excavatum, widely spaced nipples and normal external genitalia. He had broad and short hands and feet, brachydacyly of fingers and toes, as well as 2nd/3rd syndactyly and clinodactyly of 5th fingers. Neurological examination normal. Developmental delay with poor social contact. Radiologic studies confirmed brachycephaly, short hands showing coarse metacarpal bones, slight platyspondyly and mild generalized osteoporosis.
The mother had a borderline IQ, a coarse facies with upslanting palpebral fissures and broad nose with hypoplastic nares. She had a short neck, asymmetric thorax with rib retraction and hypoplasia on the left side, with lowering of left shoulder. There was a slight pectus excavatum and hypoplasia of the pectorals muscle. The radiological studies confirmed the described skeletal anomalies, as well as platyspondyly. The father was normal.
20-
CW-
6
male/
prenatal
AF de novo 48,XY,+marx2[11]/
47,XY,+mar[4]
mar(20) n.a. AMA; positive maternal marker serum screen; child born and at 1y DD and DYS {27} case 75
20-
CW-
7
n.a./
prenatal
AF de novo 47,+mar[?%] r(20) n.a. abnormal sonography; TOP {44} 1 case
20-
CW-
8
female/
2y
PBL de novo 47,XX,+mar[?100%] min(20) cep probes short stature, minor DYS and global DD {49}
20-
CW-
9
n.a./
10y
PBL n.a. 47,+mar[100%] min(20) SKY DD, autism {52} case F0549359
20-
CW-
10
female/
8y
PBL n.a. 47,XX,+mar[?%]/
46,XX,[?%]
min(20) SKY DD, MR, trigonocephaly {52} case F0549359

Cases with isochromosome 20p (W-iso)
isochromosome 20p may appear in normal fetus only restricted to bladder and then be detected in amnion

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
20-
W
-
iso
/
1-1
male/
prenatal
AF and PBL de novo 47,XY,+mar[73%]/
46,XY[27%]
at birth sSMC in 30% of PBL
inv dup(20)(q11.2) aCGH Osteopenia, osteoporosis, IUGR, DD, strabism, abnormal ears, etc. {65}
20-
W
-
iso
/
1-2
female/
prenatal
chord blood de novo 47,XX,+inv dup(20)(q11) n.a. n.a. multiple defects in sonography; TOP {50; 63}
20-
W
-
iso
/
1-3
female/
prenatal
CVS de novo 47,XX,+i(20)(p10) n.a. n.a. multiple defects in sonography; TOP {51}
20-
W
-
iso
/
1-4
female/
prenatal
AF? de novo 47,XX,+inv dup(20)(q11)[80.3%]/
46,XX[19.7%]
n.a. n.a. micrognathia, microcephaly, IUGR; TOP {15} case VIIc-6