Mutated genes and variants type
The low-cost targeted gene-panel designed for ID/ASD enabled us to obtain high-quality sequencing data, with a coverage > 100x in the targeted regions. In our cohort we identified 60 pathogenic/likely pathogenic variants (Table 2) and 49 Variants of Uncertain Significance (VUS) (Table 3). The reported variants map to 45 different genes (Fig. 1). For 16 genes, variants were detected in more than two patients. ANKRD11 was the most frequently mutated gene, with seven detected variants. MECP2 variants were found in six individuals, and ARID1B, ASH1L, CHD8, KDM5C, MED12 and PTCHD1 each had variants in five cases. Out of the 60 (14.5%) patients with pathogenic/likely pathogenic variants, 18 had a reported family history, 17 patients were sporadic, while family information was unavailable for 25 patients. Most of the pathogenic variants (n = 44; 73%) were de novo, three inherited from mildly affected parents, three were not inherited from the single available parent, and for 16.6% (n = 10) of the variants, inheritance could not be assessed (Table 1). The majority of pathogenic variants, 36 out of 60, are loss-of-function (LoF) variants. Specifically, 16 introduce a novel stop codon, 20 are frameshift insertions or deletions, and 22 variants are missense. Among them we identified the somatic mosaicism variant p.(Arg504Gln) in GRIN2A. Targeted next generation sequencing on the proband’s blood sample and oral mucosa cells allowed for the estimation of a mosaicism of 25% (Fig. 2). Additionally, we identified a novel de novo non-frameshift substitution variant in the DEAF1 gene p.(Pro237_Thr238delinsSerSer) and one de novo deep intronic variant (c.4956-17A > G) in MED13L which impacts the splicing mechanism (Fig. 3). Most pathogenic and likely pathogenic variants were identified in patients whose clinical phenotype matched the mutated gene. In other individuals, we observed clinical features that were atypical for the mutated genes (Table 4).
Table 2
Pathogenic/Likely Pathogenic variants found in 415 paediatric patients.
P
|
S
|
GENE
|
INH
|
ZYG
|
VFS
|
FH
|
Type
|
Ref Seq
|
Variant
|
dbSNP
|
Clinvar
|
MAF
|
CP
|
CADD
|
GERP
|
0107
|
F
|
ADNP
|
AD
|
HT
|
DN
|
-
|
MIS
|
NM_001282531.3
|
c.2473G > C
p.(Gly825Arg)
|
-
|
-
|
-
|
8
|
25
|
5.1
|
0129
|
M
|
ADNP
|
AD
|
HT
|
-
|
-
|
FS
|
NM_001282531.3
|
c.2232_2236del
p.(Glu744AspfsTer2)
|
-
|
-
|
-
|
-
|
.
|
.
|
0072
|
M
|
ADNP
|
AD
|
HT
|
DN
|
-
|
FS
|
NM_001282531.3
|
c.539_542del
p.(Val180GlyfsTer17)
|
rs1057518345
|
P
|
-
|
-
|
.
|
.
|
0291
|
M
|
ANKRD11
|
AD
|
HT
|
DN
|
-
|
MIS
|
NM_013275.6
|
c.7606C > T
p.(Arg2536Trp)
|
rs2151701893
|
P/LP
|
-
|
9
|
29
|
1.7
|
0256
|
M
|
ANKRD11
|
AD
|
HT
|
DN
|
-
|
FS
|
NM_013275.6
|
c.5973_5997del
p.(Lys1992SerfsTer87)
|
-
|
-
|
-
|
-
|
.
|
.
|
0205
|
F
|
ANKRD11
|
AD
|
HT
|
DN
|
-
|
FS
|
NM_013275.6
|
c.4396_4397del
p.(Arg1466GlyfsTer87)
|
-
|
-
|
-
|
-
|
.
|
.
|
0171
|
F
|
ANKRD11
|
AD
|
HT
|
-
|
-
|
STOP
|
NM_013275.6
|
c.2446G > T
p.(Glu816Ter)
|
-
|
-
|
-
|
-
|
37
|
5.7
|
0212
|
F
|
ANKRD11
|
AD
|
HT
|
DN
|
-
|
FS
|
NM_013275.6
|
c.2165_2166del
p.(Lys722ArgfsTer19)
|
-
|
-
|
-
|
-
|
.
|
.
|
0330
|
F
|
ANKRD11
|
AD
|
HT
|
Absent in healthy sister
|
-
|
FS
|
NM_013275.6
|
c.1903_1907del
p.(Lys635GlnfsTer26)
|
rs886041125
|
P
|
-
|
-
|
.
|
.
|
0242
|
M
|
ANKRD11
|
AD
|
HT
|
DN
|
-
|
FS
|
NM_013275.6
|
c.281_284del
p.(Ala94GlyfsTer29)
|
-
|
-
|
-
|
-
|
.
|
.
|
0142
|
F
|
ARID1B
|
AD
|
HT
|
-
|
-
|
STOP
|
NM_001374828.1
|
c.1996C > T
p.(Gln666Ter)
|
rs1554265250
|
-
|
-
|
-
|
40
|
5.5
|
0105
|
F
|
ARID1B
|
AD
|
HT
|
DN
|
-
|
STOP
|
NM_001374828.1
|
c.3673C > T
p.(Arg1225Ter)
|
rs387907141
|
P
|
-
|
-
|
40
|
5.0
|
0408
|
F
|
ARID1B
|
AD
|
HT
|
DN
|
-
|
FS
|
NM_001374828.1
|
c.4964_4974del
p.(Ile1655ThrfsTer100)
|
-
|
-
|
-
|
-
|
.
|
.
|
0093
|
M
|
ARID1B
|
AD
|
HT
|
DN
|
-
|
MIS
|
NM_001374828.1
|
c.6775T > C
p.(Ser2259Pro)
|
rs1057521854
|
LP
|
-
|
7
|
27
|
5.5
|
0141
|
M
|
ASH1L
|
AD
|
HT
|
DN
|
-
|
MIS
|
NM_018489.3
|
c.3893T > G
p.(Leu1298Arg)
|
-
|
-
|
-
|
11
|
26
|
4.9
|
0337
|
M
|
ASH1L
|
AD
|
HT
|
DN
|
-
|
MIS
|
NM_018489.3
|
c.3179A > G
p.(Asn1060Ser)
|
rs1665817487
|
-
|
-
|
6
|
23
|
5.1
|
0390
|
M
|
CHD8
|
AD
|
HT
|
-
|
-
|
FS
|
NM_001170629.2
|
c.7148del
p.(Pro2383GlnfsTer47)
|
-
|
-
|
-
|
-
|
.
|
.
|
0393
|
F
|
CHD8
|
AD
|
HT
|
DN
|
-
|
MIS
|
NM_001170629.2
|
c.6997C > T
p.(Arg2333Cys)
|
rs1887539639
|
-
|
-
|
6
|
32
|
5.4
|
0336
|
F
|
CHD8
|
AD
|
HT
|
DN
|
-
|
MIS
|
NM_001170629.2
|
c.2282G > T
p.(Trp761Leu)
|
.
|
-
|
-
|
11
|
29
|
5.0
|
0062
|
M
|
CHD8
|
AD
|
HT
|
DN
|
-
|
STOP
|
NM_001170629.2
|
c.1174C > T
p.(Gln392Ter)
|
rs1555318204
|
-
|
-
|
-
|
36
|
5.4
|
0246
|
M
|
CTNNB1
|
AD
|
HT
|
-
|
-
|
FS
|
NM_001904.4
|
c.160dup
p.(Glu54GlyfsTer12)
|
-
|
-
|
-
|
-
|
.
|
.
|
0395
|
F
|
DEAF1
|
AD/AR
|
HT
|
DN
|
-
|
MIS
|
NM_021008.4
|
c.782G > C
p.(Arg261Pro)
|
-
|
-
|
-
|
11
|
25
|
4.5
|
0172
|
F
|
DEAF1
|
AD/AR
|
HT
|
DN
|
-
|
nonFS
|
NM_021008.4
|
c.709_712delinsTCCT
p.(Pro237_Thr238delinsSerSer)
|
-
|
-
|
-
|
-
|
.
|
.
|
0362
|
M
|
DYRK1A
|
AD
|
HT
|
DN
|
-
|
STOP
|
NM_001347721.2
|
c.427G > T
p.(Gly143Ter)
|
rs1463551651
|
-
|
-
|
-
|
37
|
5.2
|
0331
|
F
|
DYRK1A
|
AD
|
HT
|
DN
|
-
|
STOP
|
NM_001347721.2
|
c.664C > T
p.(Arg222Ter)
|
rs780441716
|
P
|
-
|
-
|
|
5.6
|
0112
|
M
|
EHMT1
|
AD
|
HT
|
DN
|
-
|
MIS
|
NM_024757.5
|
c.3186C > G
p.(Cys1062Trp)
|
-
|
-
|
-
|
11
|
23
|
0.1
|
0399
|
M
|
FOXP1
|
AD
|
HT
|
DN
|
-
|
STOP
|
NM_001349338.3
|
c.1630C > T
p.(Arg544Ter)
|
-
|
P
|
-
|
-
|
38
|
4.0
|
0351
|
M
|
FOXP1
|
AD
|
HT
|
DN
|
-
|
FS
|
NM_001349338.3
|
c.1590dup
p.(Gly531ArgfsTer8)
|
-
|
-
|
-
|
-
|
.
|
.
|
0407
|
F
|
FOXP1
|
AD
|
HT
|
DN
|
-
|
STOP
|
NM_001349338.3
|
c.1526G > A
p.(Trp509Ter)
|
rs780157776
|
-
|
-
|
-
|
47
|
5.9
|
0286
|
M
|
GATAD2B
|
AD
|
HT
|
DN
|
-
|
MIS
|
NM_020699.4
|
c.922T > G
p.(Cys308Gly)
|
-
|
-
|
-
|
3
|
23
|
5.1
|
0010
|
F
|
GRIN2A
|
AD
|
MOS
|
DN
|
-
|
MIS
|
NM_001134407.3
|
c.1511G > A
p.(Arg504Gln)
|
rs1331671132
|
VUS
|
-
|
6
|
24
|
5.3
|
0110
|
F
|
KDM5C
|
XL
|
HT
|
DN
|
-
|
MIS
|
NM_004187.5
|
c.3794T > C
p.(Leu1265Pro)
|
-
|
-
|
-
|
9
|
27
|
4.8
|
0243
|
M
|
KDM5C
|
XL
|
HE
|
MAT
|
-
|
STOP
|
NM_004187.5
|
c.2851C > T
p.(Arg951Ter)
|
rs1556837277
|
P
|
-
|
-
|
36
|
3.8
|
0366
|
F
|
KDM5C
|
XL
|
HT
|
DN
|
-
|
MIS
|
NM_004187.5
|
c.1795C > T
p.(Arg599Cys)
|
rs1556842184
|
LP
|
-
|
9
|
29
|
5.7
|
0388
|
M
|
MBD5
|
AD
|
HT
|
DN
|
-
|
FS
|
NM_001378120.1
|
c.24del
p.(Asp8GlufsTer75)
|
-
|
-
|
-
|
-
|
.
|
.
|
0140
|
F
|
MECP2
|
XL
|
HT
|
DN
|
-
|
STOP
|
NM_004992.4
|
c.808C > T
p.(Arg270Ter)
|
rs61750240
|
P
|
-
|
-
|
37
|
.
|
0267
|
F
|
MECP2
|
XL
|
XXX
|
-
|
-
|
STOP
|
NM_004992.4
|
c.808C > T
p.(Arg270Ter)
|
rs61750240
|
P
|
-
|
-
|
37
|
3.7
|
0411
|
F
|
MECP2
|
XL
|
HT
|
-
|
-
|
STOP
|
NM_004992.4
|
c.763C > T
p.(Arg255Ter)
|
rs61749721
|
P
|
-
|
-
|
38
|
3.5
|
0118
|
F
|
MECP2
|
XL
|
HT
|
-
|
-
|
MIS
|
NM_004992.4
|
c.473C > T
p.(Thr158Met)
|
rs28934906
|
P/LP
|
-
|
11
|
27
|
5.5
|
0081
|
F
|
MECP2
|
XL
|
HT
|
-
|
-
|
MIS
|
NM_004992.4
|
c.316C > T
p.(Arg106Trp)
|
rs28934907
|
P/LP
|
-
|
12
|
26
|
2.8
|
0210
|
M
|
MED12
|
XLD
|
HE
|
-
|
+
|
MIS
|
NM_005120.3
|
c.4147G > A
p.(Ala1383Thr)
|
rs863223696
|
P
|
-
|
9
|
29
|
4.4
|
0383
|
M
|
MED13L
|
AD
|
HT
|
DN
|
-
|
SP
|
NM_015335.5
|
c.4956-17A > G
p.Ser1652Argfs*1
|
-
|
-
|
-
|
-
|
.
|
.
|
0014
|
M
|
PHF21A
|
AD
|
HT
|
DN
|
-
|
FS
|
NM_001352027.3
|
c.1032_1035del
p.(Thr345ArgfsTer28)
|
rs2092369866
|
P
|
-
|
-
|
.
|
.
|
0056
|
M
|
PPP2R5D
|
AD
|
HT
|
DN
|
-
|
MIS
|
NM_006245.4
|
c.598G > A
p.(Glu200Lys)
|
rs863225079
|
P/LP
|
-
|
9
|
32
|
5.7
|
0169
|
F
|
PTCHD1
|
XL
|
HT
|
DN
|
-
|
MIS
|
NM_173495.3
|
c.2072G > A
p.(Arg691Gln)
|
rs1569143368
|
-
|
-
|
5
|
23
|
5.3
|
0104
|
M
|
PTCHD1
|
XL
|
HE
|
MAT
|
+
|
STOP
|
NM_173495.3
|
c.2289C > A
p.(Tyr763Ter)
|
-
|
-
|
-
|
-
|
35
|
3.4
|
0109
|
M
|
PTEN
|
AD
|
HT
|
DN
|
-
|
MIS
|
NM_000314.8
|
c.103A > G
p.(Met35Val)
|
rs876659443
|
P
|
-
|
12
|
25
|
5.2
|
0309
|
M
|
SATB2
|
AD
|
HT
|
DN
|
-
|
FS
|
NM_001172509.2
|
c.1105_1106insT
p.(Arg369MetfsTer3)
|
-
|
-
|
-
|
-
|
.
|
.
|
0240
|
M
|
SETBP1
|
AD
|
HT
|
DN
|
-
|
STOP
|
NM_015559.3
|
c.1765C > T
p.(Arg589Ter)
|
rs1568235086
|
P/LP
|
-
|
-
|
39
|
6.1
|
0418
|
F
|
SHANK2
|
AD
|
HT
|
DN
|
-
|
FS
|
NM_133266.5
|
c.2989_3004del
p.(Pro997SerfsTer38)
|
-
|
-
|
-
|
-
|
.
|
.
|
0333
|
F
|
SHANK3
|
AD
|
HT
|
DN
|
-
|
FS
|
NM_0033517.1
|
c.4637_4638del
p.(Phe1563GlnfsTer5)
|
-
|
-
|
-
|
-
|
.
|
.
|
0114
|
M
|
SLC6A1
|
AD
|
HT
|
NOT MAT
|
-
|
MIS
|
NM_003042.4
|
c.855G > T
p.(Trp285Cys)
|
-
|
-
|
-
|
11
|
31
|
4.9
|
0047
|
M
|
SLC6A1
|
AD
|
HT
|
DN
|
-
|
MIS
|
NM_003042.4
|
c.919G > A
p.(Gly307Arg)
|
rs1553689696
|
P/LP
|
-
|
11
|
26
|
4.8
|
0034
|
M
|
SLC6A1
|
AD
|
HT
|
MAT
|
+
|
MIS
|
NM_003042.4
|
c.1084G > A
p.(Gly362Arg)
|
rs1131691302
|
LP
|
-
|
11
|
25
|
4.9
|
0299
|
F
|
SYNGAP1
|
AD
|
HT
|
DN
|
-
|
FS
|
NM_006772.3
|
c.431_434del
p.(Thr144SerfsTer29)
|
-
|
-
|
-
|
-
|
.
|
.
|
0170
|
M
|
SYNGAP1
|
AD
|
HT
|
DN
|
-
|
FS
|
NM_006772.3
|
c.2473_2474dup
p.(Asp826ArgfsTer11)
|
-
|
-
|
-
|
-
|
.
|
.
|
0288
|
F
|
SYNGAP1
|
AD
|
HT
|
DN
|
-
|
FS
|
NM_006772.3
|
c.3778_3779del
p.(Lys1260GlufsTer22)
|
-
|
-
|
-
|
-
|
.
|
.
|
0200
|
F
|
UBE3A
|
AD
|
HT
|
DN
|
-
|
FS
|
NM_130839.5
|
c.2571_2574dup
p.(Leu859GlufsTer23)
|
-
|
-
|
-
|
-
|
.
|
.
|
0391
|
M
|
WAC
|
AD
|
HT
|
DN
|
-
|
STOP
|
NM_016628.5
|
c.139C > T
p.(Arg47Ter)
|
rs368543869
|
P
|
-
|
-
|
36
|
3.7
|
0148
|
F
|
WAC
|
AD
|
HT
|
NOT PAT
|
-
|
STOP
|
NM_016628.5
|
c.374C > A
p.(Ser125Ter)
|
rs864321692
|
P
|
-
|
-
|
38
|
5.8
|
Abbreviations: P, patient code; S, sex; INH, mode of inheritance; ZYG, zygosity; VFS, Variant Family Segregation; FH, familial history; Ref Seq, reference sequence; MAF, minor allele frequency; CP. consensus prediction among 12 computational tools provided by Annovar; CADD, Combined Annotation Dependent Depletion score; GERP, genomic evolutionary rate profiling score; M, Male; F, Female; AD, autosomal dominant; AR, autosomal recessive; XL, X-linked; HT, heterozygous; HE, hemizygous; MOS, mosaicism; DN, de novo; MAT, maternal; PAT, paternal; MIS, missense; FS, frameshift; P, pathogenic; LP, likely pathogenic
Table 3
Variants of Uncertain Significance found in 415 paediatric patients.
P
|
S
|
GENE
|
INH
|
ZYG
|
VFS
|
XCI
|
Type
|
Ref Seq
|
Variant
|
dbSNP
|
Clinvar
|
MAF
|
CP
|
CADD
|
GERP
|
HSF
|
215
|
M
|
AP1S2
|
XL
|
HE
|
-
|
-
|
SYN
|
NM_003916.5
|
c.240G > A
p.(Leu80Leu)
|
rs912444495
|
-
|
-
|
-
|
-
|
-
|
ESE site broken, New cryptic acceptor site
|
222
|
M
|
ARID1B
|
AD
|
HT
|
-
|
-
|
MIS
|
NM_001374828.1
|
c.1031C > T
p.(Pro344Leu)
|
-
|
-
|
-
|
5
|
24.8
|
2.78
|
-
|
385
|
M
|
ASH1L
|
AD
|
HT
|
-
|
-
|
MIS
|
NM_018489.3
|
c.2950C > T
p.(Arg984Cys)
|
rs548853139
|
-
|
0.00002005
|
10
|
27.2
|
5.16
|
-
|
FOXP1
|
AD
|
HT
|
-
|
-
|
MIS
|
NM_001349338.3
|
c.1667T > C
p.(Ile556Thr)
|
rs751381124
|
-
|
0.000003976
|
7
|
24.3
|
6.13
|
-
|
19
|
M
|
ASH1L
|
AD
|
HT
|
-
|
-
|
MIS
|
NM_018489.3
|
c.6916C > T
p.(Arg2306Trp)
|
rs142371619
|
-
|
7.311e-05
|
11
|
31
|
4.96
|
-
|
400
|
F
|
ASH1L
|
AD
|
HT
|
-
|
-
|
MIS
|
NM_018489.3
|
c.7543C > T
p.(Arg2515Trp)
|
rs747531593
|
-
|
0.00001996
|
9
|
32
|
2.74
|
-
|
84
|
M
|
ATRX
|
XL
|
HE
|
MAT
|
MAT, 32:68
|
MIS
|
NM_000489.6
|
c.4196A > G
p.(Glu1399Gly)
|
-
|
-
|
-
|
9
|
24.5
|
5.24
|
-
|
296
|
M
|
ATRX
|
XL
|
HE
|
MAT
|
MAT, 26:74
|
MIS
|
NM_000489.6
|
c.4407T > A
p.(Asp1469Glu)
|
-
|
-
|
-
|
8
|
22.5
|
2.46
|
-
|
359
|
M
|
CASK
|
XL
|
HE
|
MAT
|
random
|
MIS
|
NM_001367721.1
|
c.44G > A
p.(Cys15Tyr)
|
-
|
-
|
-
|
5
|
23.9
|
4.88
|
-
|
127
|
M
|
CASK
|
XL
|
HE
|
MAT
|
MAT, 32:68
|
MIS
|
NM_001367721.1
|
c.2640C > A
p.(Asp880Glu)
|
-
|
-
|
-
|
3
|
12.3
|
0.197
|
-
|
374
|
M
|
CHD8
|
AD
|
HT
|
-
|
-
|
MIS
|
NM_001170629.2
|
c.203C > A
p.(Pro68His)
|
-
|
-
|
-
|
4
|
23.5
|
4.78
|
-
|
273
|
F
|
CNTNAP2
|
AD/AR
|
HT
|
PAT
|
-
|
MIS
|
NM_014141.6
|
c.511C > T
p.(Arg171Cys)
|
rs375032955
|
VUS
|
4.47E-02
|
11
|
25.7
|
5.47
|
-
|
HT
|
MAT
|
-
|
SYN
|
NM_014141.6
|
c.2517T > C
p.(Asn839=)
|
rs143358892
|
LB
|
0.00007075
|
-
|
-
|
-
|
-
|
268
|
M
|
CNTNAP2
|
AD/AR
|
HT
|
-
|
-
|
MIS
|
NM_014141.6
|
c.2368C > A
p.(Arg790Ser)
|
rs200089329
|
VUS
|
-
|
8
|
27
|
5.6
|
-
|
223
|
M
|
DEAF1
|
AD/AR
|
HT
|
-
|
-
|
SP?
|
NM_021008.4
|
c.805-31C > G
p.?
|
-
|
-
|
-
|
-
|
-
|
-
|
Broken Branch Point
|
401
|
F
|
DEAF1
|
AD/AR
|
HT
|
-
|
-
|
MIS
|
NM_021008.4
|
c.908G > T
p.(Arg303Leu)
|
-
|
VUS
|
-
|
9
|
28.6
|
3.65
|
-
|
KATNAL2
|
AD
|
HT
|
-
|
-
|
MIS
|
NM_001387690.1
|
c.1084A > G
p.(Arg362Gly)
|
-
|
-
|
-
|
12
|
29.6
|
4.8
|
-
|
330
|
F
|
EHMT1
|
AD
|
HT
|
healthy sister negative
|
-
|
MIS
|
NM_024757.5
|
c.103G > A
p.(Asp35Asn)
|
rs371134699
|
VUS
|
0.00003081
|
9
|
25.3
|
5.41
|
-
|
170
|
M
|
GRIA3
|
XL
|
HE
|
MAT
|
MAT,74:26
|
MIS
|
NM_000828.5
|
c.2053G > A
p.(Gly685Ser)
|
-
|
-
|
-
|
6
|
25.3
|
5:45
|
-
|
345
|
M
|
GRIK2
|
AD/AR
|
HT
|
-
|
-
|
MIS
|
NM_021956.5
|
c.205A > G
p.(Thr69Ala)
|
-
|
VUS
|
8.154e-06
|
7
|
22
|
5.67
|
-
|
380
|
F
|
GRIN2A
|
AD
|
HT
|
-
|
-
|
MIS
|
NM_001134407.3
|
c.3163G > C
p.(Glu1055Gln)
|
rs370107080
|
VUS
|
0.00001591
|
8
|
26.1
|
5.33
|
-
|
378
|
M
|
GRIN2B
|
AD
|
HT
|
-
|
-
|
MIS
|
NM_000834.5
|
c.2557G > A
p.(Val853Ile)
|
rs201477697
|
-
|
-
|
4
|
26
|
5.76
|
-
|
179
|
F
|
GRIN2B
|
AD
|
HT
|
-
|
-
|
MIS
|
NM_000834.5
|
c.4259A > G
p.(Asp1420Gly)
|
-
|
-
|
-
|
6
|
27
|
5.23
|
-
|
59
|
M
|
IL1RAPL1
|
XL
|
HE
|
MAT
|
-
|
MIS
|
NM_014271.4
|
c.735G > C
p.(Leu245Phe)
|
-
|
-
|
-
|
4
|
21.2
|
4.14
|
-
|
160
|
F
|
IQSEC2
|
XL
|
HT
|
-
|
-
|
MIS
|
NM_001111125.3
|
c.322C > T
p.(His108Tyr)
|
-
|
-
|
-
|
4
|
23.4
|
2.81
|
-
|
85
|
F
|
IQSEC2
|
XL
|
HT
|
-
|
98:2
|
SYN
|
NM_001111125.3
|
c.999G > A
p.(Lys333=)
|
-
|
-
|
-
|
-
|
-
|
-
|
Alteration of the WT Donor site
|
152
|
M
|
IQSEC2
|
XL
|
HE
|
MAT
|
MAT,67:33
|
MIS
|
NM_001111125.3
|
c.2976G > T
p.(Leu992Phe)
|
-
|
-
|
-
|
5
|
|
2.21
|
-
|
279
|
M
|
KDM5C
|
XL
|
HE
|
MAT
|
MAT,71:29
|
MIS
|
NM_004187.5
|
c.835G > C
p.(Gly279Arg)
|
-
|
VUS
|
-
|
2
|
12.88
|
1:28
|
-
|
353
|
M
|
KDM5C
|
XL
|
HE
|
-
|
-
|
MIS
|
NM_004187.5
|
c.1259T > C
p.(Leu420Pro)
|
-
|
-
|
-
|
12
|
29.7
|
5.85
|
-
|
413
|
F
|
KIRREL3
|
AD
|
HT
|
-
|
-
|
MIS
|
NM_032531.4
|
c.1639G > A
p.(Ala547Thr)
|
-
|
-
|
0.000004013
|
7
|
24.8
|
5.46
|
-
|
388
|
M
|
MECP2
|
XL
|
HE
|
MAT
|
MAT,64:36
|
MIS
|
NM_004992.4
|
c.1231A > G
p.(Ser411Gly)
|
-
|
-
|
-
|
3
|
19.81
|
4.22
|
-
|
174
|
M
|
MED12
|
XL
|
HE
|
MAT
|
MAT,76:24
|
MIS
|
NM_005120.3
|
c.1994C > G
p.(Ser665Cys)
|
rs764981858
|
VUS
|
0.00001104
|
8
|
24.2
|
4.49
|
-
|
51
|
M
|
MED12
|
XL
|
HE
|
DN
|
-
|
SYN
|
NM_005120.3
|
c.3909C > T
p.(Asp1303=)
|
-
|
-
|
-
|
.
|
.
|
.
|
Altered ESE / ESS motifs ratio (-5)
|
155
|
F
|
MED12
|
XL
|
HT
|
-
|
-
|
MIS
|
NM_005120.3
|
c.4888G > A
p.(Asp1630Asn)
|
-
|
VUS
|
-
|
4
|
23.2
|
4.15
|
-
|
283
|
M
|
MED12
|
XL
|
HE
|
MAT
|
MAT,60:40
|
MIS
|
NM_005120.3
|
c.5095C > G
p.(Pro1699Ala)
|
-
|
-
|
-
|
10
|
24
|
4.17
|
-
|
390
|
M
|
MED13L
|
AD
|
HT
|
-
|
-
|
MIS
|
NM_015335.5
|
c.1367C > G
p.(Ser456Cys)
|
-
|
-
|
-
|
6
|
22.5
|
5.76
|
-
|
234
|
M
|
PPP2R5D
|
AD
|
HT
|
-
|
-
|
NONFS
|
NM_006245.4
|
c.123_140del
p.(Pro42_Gln47del)
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
21
|
F
|
PPP2R5D
|
AD
|
HT
|
-
|
-
|
MIS
|
NM_006245.4
|
c.1606A > T
p.(Thr536Ser)
|
-
|
-
|
-
|
4
|
22.6
|
5.37
|
-
|
420
|
M
|
PQBP1
|
XL
|
HE
|
MAT
|
MAT,73:28
|
MIS
|
NM_005710.2
|
c.530G > A
p.(Arg177His)
|
-
|
VUS
|
-
|
7
|
27
|
4.13
|
-
|
402
|
M
|
PTCHD1
|
XL
|
HE
|
-
|
-
|
MIS
|
NM_173495.3
|
c.605G > A
p.(Arg202Gln)
|
rs771036286
|
-
|
0.000005453
|
5
|
22
|
3.99
|
-
|
149
|
M
|
PTCHD1
|
XL
|
HE
|
MAT
|
random
|
MIS
|
NM_173495.3
|
c.751C > T
p.(Pro251Ser)
|
rs368662150
|
VUS
|
0.000005449
|
5
|
18.37
|
4.86
|
-
|
415
|
M
|
PTCHD1
|
XL
|
HE
|
MAT
|
MAT,37:63
|
MIS
|
NM_173495.3
|
c.1624A > G
p.(Thr542Ala)
|
-
|
-
|
-
|
5
|
20.4
|
5.69
|
-
|
153
|
M
|
SCN2A
|
AD
|
HT
|
-
|
-
|
MIS
|
NM_001040142.2
|
c.2496C > A
p.(Ser832Arg)
|
-
|
-
|
-
|
12
|
25.1
|
5.59
|
-
|
360
|
M
|
SLC9A6
|
XL
|
HE
|
-
|
-
|
MIS
|
NM_001042537.2
|
c.1034C > T
p.(Thr345Ile)
|
-
|
-
|
-
|
8
|
27.9
|
5.35
|
-
|
111
|
M
|
SYNGAP1
|
AD
|
HT
|
-
|
-
|
MIS
|
NM_006772.3
|
c.1003C > T
p.(Arg335Cys)
|
rs752399563
|
-
|
0.000003979
|
8
|
26.2
|
3.63
|
-
|
235
|
M
|
TANC2
|
AD
|
HT
|
-
|
-
|
MIS
|
NM_025185.4
|
c.1364A > G
p.(Tyr455Cys)
|
rs376257499
|
-
|
0.00001070
|
11
|
25
|
5.23
|
-
|
369
|
M
|
TANC2
|
AD
|
HT
|
-
|
-
|
MIS
|
NM_025185.4
|
c.2978A > G
p.(Gln993Arg)
|
-
|
-
|
-
|
8
|
26.8
|
5.78
|
-
|
325
|
M
|
TRIO
|
AD
|
HT
|
-
|
-
|
MIS
|
NM_007118.4
|
c.3641C > T
p.(Ala1214Val)
|
rs373893038
|
-
|
0.008126
|
5
|
25.8
|
5.93
|
-
|
176
|
M
|
TRIO
|
AD
|
HT
|
-
|
-
|
MIS
|
NM_007118.4
|
c.5894G > A
p.(Ser1965Asn)
|
-
|
-
|
-
|
4
|
23.3
|
5.48
|
-
|
Abbreviations: P, patient code; S, sex; INH, mode of inheritance; ZYG, zygosity; VFS, Variant Family Segregation; FH, familial history; Ref Seq, reference sequence; MAF, minor allele frequency; CP. consensus prediction among 12 computational tools provided by Annovar; CADD, Combined Annotation Dependent Depletion score; GERP, genomic evolutionary rate profiling score; M, Male; F, Female; AD, autosomal dominant; AR, autosomal recessive; XL, X-linked; HT, heterozygous; HE, hemizygous; MOS, mosaicism; DN, de novo; MAT, maternal; PAT, paternal; MIS, missense; FS, frameshift; P, pathogenic; LP, likely pathogenic; XCI: X-chromosome inactivation.
Notes: For variants identified in X-linked genes, based on the X-inactivation analysis, the % of the active mutated allele in carrier female was reported.
Table 4
Mutated genes in the different phenotypic manifestations (ASD, epilepsy, Microcephaly, Macrocephaly, Hypotonia, and Ataxia). Some genes have been found mutated in individuals presenting phenotypic traits that have not been previously associated with these genes (highlighted in bold).
Clinical features
|
Affected Individuals
|
Genes carrying Pathogenic/Likely Pathogenic variants
|
Autistic traits
|
205
|
ADNP, ARID1B, ASH1L, CHD8, DEAF1, DYRK1A, FOXP1, GRIN2A, MECP2, PHF21A, PTCHD1, RELN, SATB2, SHANK3, SLC6A1, SYNGAP1, WAC
|
Epilepsy
|
84
|
ANKRD11, CHD8, DYRK1A, EHMT1, GRIN2A, MBD5, MECP2, PHF21A, SLC6A1, SYNGAP1
|
Microcephaly
|
45
|
CHD8, EHMT1, WAC, ANKRD11, MED12, CTNNB1, MECP2, ANKRD11, DYRK1A
|
Macrocephaly
|
40
|
ADNP, FOXP1, GATAD2B, KDM5C, PPP2R5D
|
Hypotonia
|
71
|
ADNP, ANKRD11, ARID1B, CTNNB1, FOXP1, KDM5C, MECP2, SATB2, WAC
|
Ataxia
|
30
|
CHD8, DEAF1, MECP2, SYNGAP1, WAC
|
The 49 variants of uncertain significance (VUSs) selected for 14% of our cases were found in 32 different genes (Table 3). Further evidence will be required to confirm the association of these variants with the patient’s phenotype (Table 3). During the prioritisation of these variants, significant consideration is given to predictions and conservation scores such as CADD and GERP++, as well as to their frequency in the general population (e.g., gnomAD). Out of these 49 variants, 43 are missense, four are synonymous, one is intronic, and one is a non-frameshift deletion. Among the missense variants, 22 have a CADD score greater than or equal to 25, and 37 variants have a GERP + + score greater than 3 (Table 3). Among the analysed variants, 32 are not found in the population database, and 18 have a significantly low frequency. Familial inheritance has been investigated in 16 cases, while the majority (n = 33) lack segregation analysis; one of the synonymous variants has been confirmed as de novo. Among the inherited variants, except for two heterozygous variants in CNTNAP2 found in trans, the rest are mapped to X-linked genes and are maternally inherited. Most asymptomatic female carriers of X-linked gene variants showed X-inactivation favouring the wild-type allele. The four synonymous variants identified in AP1S2, IQSEC2, MED12, and CNTNAP2, and the deep intronic variant in DEAF1, are predicted to impact splicing mechanisms by Human Splicing Finder (Table 3).
Four VUSs co-occurred with pathogenic variants in four individuals. In detail, the female proband (UniPD_0330) exhibited a heterozygous rare variant p.(Asp35Asn) in EHMT1 in addition to a heterozygous ANKRD11 p.(Lys635GlnfsTer26) pathogenic variant. In this case, the healthy sister did not carry either variant. In addition to the heterozygous frameshift deletion p.(Pro2383GlnfsTer47) in CHD8, the male proband (UniPD_0390), also presented the heterozygous variant in MED13L p.(Ser456Cys). In the UniPD_0170 we found the heterozygous pathogenic frameshift variant p.(Asp826ArgfsTer11) in SYNGAP1 and the hemizygous variant p.(Gly685Ser) in GRIA3. Finally, in UniPD_0388 we detected a novel missense variant in MECP2 in hemizygous state and the heterozygous pathogenic variant p.(Asp8GlufsTer75) in MBD5. In two of these cases, UniPD_0330 and UniPD_0390, parent segregation was not possible due to adoption, resulting in uncertain significance in the interpretation of the missense variants in EHMT1 and MED13L. However, the phenotypes observed in these two cases included clinical features associated with both the pathogenic and the VUS variants. In the other two cases, UniPD_0170 and UniPD_0388, the XCI analysis supports the pathogenicity of the variants in the X-linked genes, MECP2 and GRIA3 (Table 3).
Finally, in 82 patients, we identified variants in 14 genes, such as RELN, KATNAL2, MIB1, associated with autism susceptibility, with low penetrance or with limited information about their involvement in NDDs. These variants were classified by Padua NDD laboratory as Risk Factors (Supplementary Table S2).
The cohort of individuals selected for the sixth edition of the Critical Assessment of Genome Interpretation (CAGI6) shows clinical characteristics similar to those of the population used in the previous CAGI5 edition (Aspromonte et al., 2019). Among patients with cognitive assessment, a higher distribution of individuals with mild to moderate intellectual disability (ID) is observed—specifically, 31% and 28% respectively—compared to 22% and 25.3% in the CAGI5 cohort (Table 4). In the CAGI6 cohort, a lower percentage of patients had Autism Spectrum Disorder (ASD) or epilepsy, specifically 49% and 20% respectively, compared to 62% and 36.6% in the CAGI5 cohort. On the other hand, patients with macrocephaly are more represented in CAGI6, accounting for 10% compared to 7.3% in CAGI5.
The two cohorts slightly differ in the proportion of pathogenic variants we were able to identify, with 17,3% in CAGI5 and 14.5% in CAGI6; while the number of variants with a likely although not established pathogenic role is higher in the CAGI6 (13%) compared to the previous one (10%).