Jou nal o
Clinical Medicine
A icle
O al Mani es a ions o Wol -Hi schho n Synd ome:
Geno ype-Pheno ype Co ela ion Analysis
Jacobo Lime es 1, Candela Se ano 1, Joaquin Manuel De No a 2, Ja ie Sil es e-Rangil 3,
Guille mo Machuca 4, Isabel Mau a 5, Jose C uz Ruiz-Villandiego 6, Ped o Diz 1,*,
Raquel Blanco-Lago 7, Julian Ne ado 8,9,10 and Ma cio Diniz-F ei as 1
1Medical-Su gical Den is y Resea ch G oup (OMEQUI), Heal h Resea ch Ins i u e o San iago
de Compos ela (IDIS), Uni e si y o San iago de Compos ela (USC), 15782 San iago de Compos ela, Spain;
[email p o ec ed] (J.L.); [email p o ec ed] (C.S.); ma [email p o ec ed] (M.D.-F.)
2Depa men o S oma ology IV, School o Den is y, Uni e si y Complu ense de Mad id, 28040 Mad id,
Spain; [email p o ec ed]
3
Depa men o S oma ology, Uni e si y Hospi al Doc o Pese -FISABIO, 46017 Valencia, Spain; sil anja@u .es
4Depa men o Special Ca e in Den is y, School o Den is y, Uni e si y o Se ille, 41009 Se illa, Spain;
[email p o ec ed]
5Se ice o Pedia ic Den is y, Ba celona Uni e si y Child en’s Hospi al HM Nens, 08009 Ba celona, Spain;
[email p o ec ed]
6Se ice o Special Ca e in Den is y, Qui ón Hospi al, 200012 San Sebas ián, Spain; [email p o ec ed]
7Se ice o Neu opedia ics, Uni e si y Hospi al Cen al de As u ias, 33011 O iedo, Spain;
[email p o ec ed]
8Medical and Molecula Gene ics Ins i u e (INGEMM), La Paz Uni e si y Hospi al, IdiPAZ, 28046 Mad id,
Spain; [email p o ec ed]
9Ins i u e o Ra e Diseases Resea ch (IIER) & Cen e o Biomedical Ne wo k Resea ch on Ra e
Diseases (CIBERER), Ins i u o de Salud Ca los III, 28029 Mad id, Spain
10 ERN (Eu opean Re e ence Ne wo k)-ITHACA, La Paz Uni e si y Hospi al, 28046 Mad id, Spain
*Co espondence: Ped [email p o ec ed]
Recei ed: 24 Sep embe 2020; Accep ed: 31 Oc obe 2020; Published: 4 No embe 2020


Abs ac :
Backg ound: Wol -Hi schho n synd ome (WHS) is a a e disease caused by dele ion in
he dis al moie y o he sho a m o ch omosome 4. The objec i es o his s udy we e o epo
he mos ep esen a i e o al indings o WHS, ela e hem wi h o he clinical cha ac e is ics o
he disease, and es ablish possible pheno ype-geno ype co ela ion. Me hods: The s udy was
conduc ed a 6 e e ence cen e s dis ibu ed h oughou Spain du ing 2018–2019. The s udy
g oup consis ed o 31 pa ien s wi h WHS who unde wen a s anda dized o al examina ion.
Due o beha io al easons, imaging s udies we e pe o med on only 11 o he child en 6 yea s
o age o olde . All pa icipan s had p e iously unde gone a speci ic medical examina ion
o WHS, du ing which ana omical, unc ional, epilepsy- ela ed, and gene ic a iables we e
eco ded. Resul s: The mos p e alen o al mani es a ions we e delayed oo h e up ion (74.1%),
b uxism (64.5%), den al agenesis (63.6%), mic ogna hia (60.0%), oligodon ia (45.5%), and
down u ned co ne s o he mou h (32.3%). We de ec ed s ong co ela ion be ween psychomo o
delay and oligodon ia (p=0.008; C am
é
’s V coe icien , 0.75). The size o he dele ion was
co ela ed in a s a is ically signi ican manne wi h he p esence o oligodon ia (
p=0.009
;
poin -bise ial co ela ion coe icien , 0.75). Conclusion: Ce ain o al mani es a ions p e alen in
WHS can o m pa o he synd ome’s pheno ypic a iabili y. A numbe o he cha ac e is ics
o WHS, such as psychomo o delay and epilepsy, a e co ela ed wi h o al indings such
as oligodon ia and b uxism. Al hough mos geno ype-pheno ype co ela ions a e cu en ly
unknown, mos o hem seem o be associa ed wi h la ge dele ions, sugges ing ha some
o al- acial candida e genes migh be ou side he c i ical WHS egion, indica ing ha WHS is a
con iguous gene synd ome.
J. Clin. Med. 2020,9, 3556; doi:10.3390/jcm9113556 www.mdpi.com/jou nal/jcm
J. Clin. Med. 2020,9, 3556 2 o 14
Keywo ds:
Wol -Hi schho n synd ome; 4p-; s oma ogna hic diseases; o al mani es a ions; geno ype
1. In oduc ion
Wol -Hi schho n synd ome (WHS) is a de elopmen al diso de caused by sub elome ic dele ion
in he dis al egion o he sho a m o ch omosome 4 (4p16.3) [
1
]. Ch omosomal mic oa ay
echniques showed ha a conside able pe cen age o pa ien s ha e o he cy ogene ic abe a ions in
addi ion o dele ion, such as unbalanced de no o ansloca ions, in e ed duplica ions, and pe icen ic
in e sions [2–5].
The disease is conside ed a e and has an es ima ed p e alence o 1/50.000 bi hs, wi h a
p edominance among he emale sex o 2:1 [
6
]. Al hough pa ien s wi h WHS ha e agile heal h o he
i s yea s o hei li e, hei mean li e expec ancy is mo e han 30 yea s [
7
]. To da e, mo e han 300 cases
o WHS ha e been documen ed in he medical li e a u e, which helped cha ac e ize i s pheno ypic
spec um [
7
]. An almos pa hognomonic inding in hese pa ien s is he cha ac e is ic “G eek wa io
helme ” acies, which consis s o a p ominen glabella, wide o ehead, a ched eyeb ows, hype elo ism,
exoph halmos, epican hal olds, wide nasal b idge, la ge nose, sho phil um, mic ogna hia, and a
la ge mou h wi h down u ned co ne s (Figu e 1) [
8
]. In addi ion o his unique acial pheno ype, he
undamen al mani es a ions o his polymal o ma i e synd ome in i s “classical” p esen a ion include
de elopmen al delay, in ellec ual disabili y, and epilepsy [9].
Figu e 1. Wol -Hi schho n synd ome wi h cha ac e is ic “G eek wa io helme ” acial pheno ype.
The co e WHS pheno ype is due o he haploinsu iciency o se e al in ima ely ela ed genes, which
include WHSC1, WHSC2, SLBP, and LETM1 [
2
,
3
]. Subsequen ly, addi ional genes we e iden i ied o
which he dele ion is necessa y o he pheno ypic exp ession o be comple e, which include FGFRL1,
CPLX1, CTBP1 and PIGG [
5
,
10
]. A numbe o hese genes, such as WHSC1 and FGFRL1, a e conside ed
candida es o de e mining he c anio acial pheno ype [
11
,
12
]. Recen s udies based on exome-sequence
analysis con i med ha poin mu a ions in he c i ical NSD2 egion (WHSC1) a e ela ed o he o o acial
pheno ype [
13
] and wi h nume ous o he cha ac e is ics o he synd ome [
14
]. Howe e , pa ien s we e
iden i ied wi h dele ions in he c i ical WHS egion (including WHSC1 and LETM1) who showed none
o he cha ac e is ic acial ea u es [
15
]. Co ela ion be ween gene ic abno mali ies and he c anio acial
pheno ype has, he e o e, s ill no been de ini i ely cla i ied.
J. Clin. Med. 2020,9, 3556 3 o 14
Up o now, he o al mani es a ions o his synd ome ha e a oused li le in e es in he
scien i ic li e a u e. Howe e , and pa adoxically, an ea ly and ini ial suspec ed diagnosis can
be es ablished on he basis o acial ai s [
16
], which equi es a ho ough examina ion o he o al
ca i y. The mos nume ous se ies published o da e on he gene al clinical mani es a ions o WHS (87
pa ien s) indica ed ha app oxima ely 50% o indi iduals wi h his disease ha e some ype o den al
abno mali y [
17
]. Ne e heless, mos o he a ailable in o ma ion in he den al li e a u e comes om
indi idual case s udies ha , in u n, we e included in na a i e e iews [
16
,
18
], excep o a se ies o 7
Finnish pa ien s wi h WHS in whom he gene ic bases o den al agenesis we e in es iga ed [19].
The aims o his c oss-sec ional s udy we e o assess he o al mani es a ions o WHS in a
con enience sample o Spanish pa ien s, and de e mine whe he he o al indings we e co ela ed wi h
o he clinical cha ac e is ics o WHS, including geno ype-pheno ype co ela ions.
2. Ma e ials and Me hods
2.1. Pa ien Selec ion
Th ough he Spanish Wol -Hi schho n Synd ome Associa ion (AESWH), we con ac ed he amilies
o 45 pa ien s wi h WHS du ing 2018–2019. The amilies we e in o med in w i ing abou he
s udy objec i es, and hei in o med consen was ob ained o using he clinical and pho og aphic
in o ma ion. The s udy was conduc ed in acco dance wi h he Decla a ion o Helsinki o he Wo ld
Medical Associa ion (2008) and app o ed by he Resea ch E hics Commi ee o La Paz Uni e si y
Hospi al, Mad id, Spain (PI-2734).
All pa icipan s had p e iously unde gone a speci ic and egula ed medical examina ion o
WHS, du ing which ana omic diso de s, clinical indings/como bidi ies, de elopmen al abno mali ies,
and epilepsy- ela ed da a we e eco ded (Table S1). These a iables had al eady been epo ed
and employed o analyzing he Spanish-based coho o WHS o which he pa ien s in his s udy
belong [4,5,20].
2.2. Single Nucleo ide Polymo phism (SNP) A ay Analysis
DNA was quan i ied using PicoG een (In i ogen Co po a ion, Ca lsbad, CA, USA).
A genomewide scan o 850,000 ag SNPs was conduc ed a he Medical and Molecula Gene ics Ins i u e
(INGEMM) using Illumina Cy oSNP-850k BeadChip acco ding o he manu ac u e ’s speci ica ions
(Illumina, San Diego, CA, USA). GenCall sco es <0.15 a any locus we e conside ed “no-calls”.
Image da a we e analyzed using he Ch omosome Viewe ool con ained in Genome S udio (Illumina,
San Diego CA, USA). The me ic ha we employed was he logR a io, which is he log (base 2) a io
o he obse ed no malized R alue o an SNP di ided by he expec ed no malized R alue (unde
he manu ac u e ’s speci ica ions). In addi ion, allele- equency analysis was applied o all SNPs,
and genomic posi ions we e based on GRCh37. We de e mined he size o he dele ion and, in cases in
which dele ion was associa ed wi h duplica ion, he size o he duplica ion.
2.3. Mul iplex Liga ion-Dependen P obe Ampli ica ion
We employed mul iplex liga ion-dependen p obe ampli ica ion (MLPA) ki p096 o de e mine
dele ions/duplica ions in he 4p16.3 egion. Reac ions we e pe o med acco ding o he manu ac u e ’s
ecommenda ions (MRC Holland, Ams e dam, The Ne he lands). P oduc s we e analyzed using a
agmen analyze sequence (ABI 3730XL; Applied Biosys ems, Fos e Ci y, CA, USA) and 500Liz
as he in e nal size s anda d. Da a analysis was pe o med using Co alyse (MRC, Ams e dam,
The Ne he lans).
2.4. Clinical and Radiological O al Examina ion
To acili a e hei pa icipa ion, we es ablished a ne wo k o 6 e e ence den al cen e s dis ibu ed
s a egically h oughou Spain (Se ille, Mad id, Valencia, Ba celona, San Sebas i
á
n, and San iago
J. Clin. Med. 2020,9, 3556 4 o 14
de Compos ela). A calib a ion mee ing was held wi h each cen e ’s ep esen a i es o eco d, in a
s anda dized manne , he pa ien s’ den al his o y, and he esul s o clinical and adiological o al
examina ion. All pa ien s 6 yea s and olde unde wen o hopan omog aphy; cone-beam compu ed
omog aphy was eques ed o hose pa ien s who p esen ed mal o ma ions o he maxillo acial bones
o suspec ed cle pala e.
We collec ed he ollowing in o ma ion om each pa ien : deg ee o coope a ion (based on he
numbe o den al eam membe s necessa y o pe o m he o al examina ion); examina ion o he o al
ca i y wi h special emphasis on he p esence o down u ned co ne s o he mou h, abno mal enula,
cle lip/pala e, ogi al pala e (high and na ow pala e), oo h-e up ion ch onology, mo phological
(e.g., peg-shaped ee h, mic odon ia), nume ical (e.g., den al agenesis, oligodon ia), and s uc u al
(e.g., enamel hypoplasia) oo h abno mali ies, and gingi al s a us (basic pe iodon al examina ion);
in e maxilla y ela ionships and oo h malocclusions in he sagi al, ans e se, and e ical planes;
and he p esence o ha m ul habi s (e.g., b uxism).
2.5. S a is ical Analysis
We employed he chi-squa ed es o s udy he associa ion be ween 2 nominal ca ego ical a iables,
and Fishe ’s exac es o s udy he associa ion be ween 2 dicho omous a iables. To de e mine he
magni ude o associa ion be ween 2 ca ego ical a iables, we applied C am
é
’s V coe icien (CVC),
which is applied o he chi-squa ed coe icien . We conside ed ha he associa ion be ween he a iables
was weak when V was
≤
0.25, mode a e when 0.25 <V<0.70, and s ong when V
≥
0.70. To quan i y
he co ela ion be ween a dicho omous and a con inuous a iable, we employed he poin -bise ial
co ela ion coe icien (CC), a de i a i e o Pea son’s co ela ion coe icien . We conside ed ha he
associa ion be ween a iables was weak when <0.30, mode a e when 0.30
≥
≤
0.70, and s ong when
>0.70. We conside ed s a is ically signi ican only hose co ela ions in which he null hypo hesis
was ejec ed in he independence es (p alue <0.05) and wi h a s ong deg ee o associa ion (CVC o
CC >0.70).
3. Resul s
The s udy g oup consis ed o 31 pa ien s (68.8% o all AESWH membe s), wi h a mean age o
9.5 ±3.6
yea s, wi h a p edominance o he emale sex (67.7%). Table 1lis s he pa icipan s’ ana omical
cha ac e is ics and hei clinical peculia i ies/como bidi ies, Table 2desc ibes he de elopmen al
abno mali ies and epilepsy cha ac e is ics, and Table 3, Figu e 2, and Table S2 show he esul s o he
gene ic s udy.
Table 1.
Ana omical cha ac e is ics and clinical indings/como bidi ies in s udy-g oup pa ien s wi h
Wol -Hi schho n synd ome (n=31).
Ana omical Va iables Como bidi ies
Sex Female n=21
(67.7%) Ca diopa hy n=13
(41.9%)
Male n=10
(23.2%) Neph ologic–u ologic abno mali ies n=18
(58.1%)
Mean age, yea s 9.5 ±3.6
(2.2–20.7) Oph halmologic mani es a ions n=19
(61.3%)
Weeks o ges a ion 30.8 ±3.3
( ange 23–39) O o hinola yngologic mani es a ions n=15
(48.4%)
Mean weigh , g * 1865.0 ±527.8
( ange 800–3440) Recu en espi a o y in ec ions n=14
(45.2%)
Mean heigh , cm * 43.3 ±3.9
( ange 34–52) Cen al ne ous sys em mal o ma ions n=15
(48.4%)
Mean c anial ci cum e ence, cm * 36.7 ±2.5
( ange 30–41) Gas os omy ca ie n=3
(9.7%)
G ow h delay n=22
71.0% O he su gical his o y n=21
(67.7%)
* A bi h.
J. Clin. Med. 2020,9, 3556 5 o 14
Table 2.
De elopmen al abno mali ies and epilepsy cha ac e is ics o s udy-g oup pa ien s wi h
Wol -Hi schho n synd ome (n=31).
De elopmen al Abno mali ies Epilepsy Cha ac e is ics
Head con ol n=30
(96.8%) Diagnosis o epilepsy n=31
(100%)
Ac i e si ing n=21
(67.7%) Age a onse , mon hs 9.9 ±5.0
( ange 0–24)
Walking wi h suppo n=20
(64.5%) Seizu es igge ed by e e n=12
(38.7.0%)
Independen walking n=11
(35.5%) Seizu es no igge ed by e e n=7
(22.5%)
Seizu es igge ed by e e and
o he condi ions
n=12
(38.7%)
Au onomous eeding n=6
(19.4%) S a us epilep icus
n=14
(45.2%)
episodes, 3.8 ±11.0
( ange 0–55)
Sphinc e con ol n=25
(80.6%)
Admission o in ensi e ca e due o
s a us epilep icus
n=11
(35.5%)
In e ac ion wi h en i onmen n=28
(90.3%) Tonic-clonic seizu es n=21
(67.7%)
Communica ion by ges u es/pic og ams
n=19
(61.3%) A ypical absences n=17
(54.8%)
Emi s single wo ds n=10
(32.3%) Seizu e- ee pe iod ≥2 yea s n=12
(38.7%)
Emi s simple ph ases n=4
(12.9%) AED use n=26
(83.9%)
Psychomo o de elopmen le el * 139.1 ±47.8
( ange 36–230) Uses AEDs in mono he apy n=17
(54.8%)
Psychomo o delay * 18.4 ±10.1
( ange 1–33) Valp oic acid use n=16
(51.6%)
Numbe o como bidi ies ha
a ec de elopmen
6.8 ±3.1
( ange 1–13) Le e i ace am use n=14
(45.1%)
AEDs, an iepilep ic d ugs; * uni s lis ed in Table S1.
Table 3. Gene ic analysis o s udy-g oup pa ien s wi h Wol -Hi schho n synd ome (n=31).
Gene ic-Al e a ion Type Numbe o Cases
Te minal dele ions
Simple 4p- e minal dele ions 16 (51.60%)
4p- e minal dele ions and
addi ional e minal duplica ions in
o he ch omosomes *
13 (41.95%)
4p- e minal dele ions and
addi ional genomic
in e s i ial duplica ions
2 (6.45%)
In e s i ial dele ions 0 (0%)
* O igina ed by unbalanced ansloca ions ei he de no o o inhe i ed. Mean size o 4p- e minal dele ions was
8.6 ±6.1 Mb ( ange, 1.9–23.5 Mb), and he mean size o addi ional duplica ions was 2.3 ±3.6 Mb ( ange, 0–15.0).

J. Clin. Med. 2020,9, 3556 6 o 14
Figu e 2.
Dele ions (black ba s) obse ed in un ela ed indi iduals wi h Wol -Hi schho n synd ome.
*, cases wi h addi ional ea angemen s. Loca ion o 4p cy ogene ic bands and known genes o hei
c i ical egion (#) p oduced using UCSC genome b owse e sion GRCh37/hg19 (In e na ional Human
Genome Sequencing Conso ium 2004).
3.1. Clinical and Radiological O al Examina ion
Fo 15 pa ien s (48.3%), he o al examina ion was pe o med wi hou o ce ul es ain , 10 (32.2%)
equi ed mode a e es ain , and 6 (19.3%) equi ed hea y es ain . O he 23 pa ien s who we e
6 yea s o age o olde , imaging s udies we e pe o med in only 11 due o beha io al easons.
Upon examining he o al ca i y, we obse ed ha 10 pa ien s (32.3%) had down u ned co ne s
o he mou h, and 4 (12.9%) had abno mal enula. We de ec ed cle lip/pala e in 5 pa ien s (16.1%),
and ogi al pala e in 5 mo e (16.1%).
Wi h ega d o den al abno mali ies, 23 pa ien s (74.1%) had delayed oo h e up ion, 8 (25.8%) had
mic odon ia, 8 (25.8%) had a leas 1 peg-shaped oo h, and 2 (6.4%) had used ee h. O he 11 pa ien s
whose age and le el o coope a ion allowed o adiological es s, 7 (63.6%) showed den al agenesis
and 5 (45.5%) showed oligodon ia (Figu e 3). The mos a ec ed ee h we e he second mola s in he
empo a y ee h and he second p emola in he pe manen ee h (Table 4). Radiological indings also
included 2 cases (18.1%) o au odon ism. We obse ed den al a i ion in 26 pa ien s (83.8%), ca ies in
7 (22.5%), and enamel hypoplasia in 3 (9.6%).
Figu e 3. Oligodon ia in a pa ien wi h Wol -Hi schho n synd ome.
J. Clin. Med. 2020,9, 3556 7 o 14
Table 4. Den al agenesis in pa ien s wi h Wol -Hi schho n synd ome.
Uppe Tee h
n(%)
Lowe Tee h
n(%)
Tempo a y ee h
n=18
La e al inciso 2 (11.1) La e al inciso -
Second mola 8 (44.4) Second mola 8 (44.4)
De ini i e ee h
n=47
Cen al inciso - Cen al inciso 2 (4.2)
La e al inciso 8 (17.0) La e al inciso 4 (8.5)
Canine - Canine 1 (2.1)
Fi s p emola 5 (10.6) Fi s p emola -
Second p emola 12 (25.5) Second p emola 7 (14.9)
Fi s mola 1 (2.1) Fi s mola -
Second mola 2 (4.2) Second mola 5 (10.6)
n, numbe o cases o den al agenesis.
O he 19 pa ien s who we e 6 yea s o age o olde and o whom he basic pe iodon al examina ion
was comple ed, 4 (21.0%) had heal hy gums, 10 (52.6%) had bleeding upon p obing, and 5 (26.3%) had
bleeding and calculi.
The examina ion o he in e maxilla y ela ionship could be comple ed in only 15 pa ien s
due o beha io al issues. We diagnosed Angle’s Class II due o mic ogna hia o e ogna hia
in 9 (60.0%) pa ien s, c ossbi e in 5 (33.3%), and o e bi e in 7 (31.8%) (Table 5). We eco ded
pe sis en b uxism in 20 pa ien s (64.5%), 7 (22.5%) had a non-nu i i e sucking habi , and 5 (16.1%)
p esen ed nibbling.
Table 5.
In e maxilla y ela ionships and oo h malocclusions in pa ien s wi h Wol -Hi schho n synd ome.
Sagi al Plane
n=15
T ans e se Plane
n=15
Ve ical Plane
n=15
n(%) n(%) n(%)
Class I 4 (26.6) No mal
occlusion 5 (33.3) No mal
occlusion 6 (40.0)
Class II 9 (60.0) C ossbi e 5 (33.3) O e bi e 7 (46.6)
Class III 2 (13.3) Scisso bi e 3 (20.0) Open bi e 2 (13.3)
O e je 4 (26.6)
An e io
c ossbi e 3 (20.0)
n, numbe o examined pa ien s; n, numbe o pa ien s who sa is ied a speci ic condi ion.
O al indings we e no co ela ed wi h each o he excep o he down u ned co ne s o he
mou h, which was mode a ely co ela ed wi h he p esence o a high-a ched (ogi al) pala e (p=0.031;
CVC, 0.37).
3.2. Co ela ions be ween Sys emic Findings, Gene ic Va iables, and O al Mani es a ions
We ound no s a is ically signi ican co ela ions be ween ana omical a iables and o al indings;
howe e , he e was mode a e posi i e co ela ion be ween weigh and mic ogna hia/Class II (p=0.040;
CC =0.57), and be ween heigh and mic ogna hia/Class II (p=0.036; CC =0.58). The e was mode a e
nega i e co ela ion be ween c anial ci cum e ence and he p esence o abno mal enula (p=0.003;
CC =
−
0.51; Table S3). We also obse ed mode a e co ela ion be ween b uxism and he pa ien ’s sex,
which sugges s a p edominance o he male sex (p=0.042; CVC =0.37; Table S3).
A e analyzing he ela ionship be ween clinical indings/como bidi ies and o al mani es a ions,
we ound no s a is ically signi ican co ela ions; howe e , we de ec ed a endency owa d co ela ion
be ween ca diac de ec s and mic ogna hia/Angle’s Class II (p=0.035; CVC =0.69; Table S4).
J. Clin. Med. 2020,9, 3556 8 o 14
In e ms o de elopmen al abno mali ies, we de ec ed s ong co ela ion be ween psychomo o
delay and oligodon ia (p=0.008; CVC =0.75; Table S5).
We ound no s a is ically signi ican co ela ions be ween epilepsy- ela ed da a and o al indings,
bu he e was mode a e co ela ion be ween spasms and abno mal enula (p=0.013; CVC =0.68) and
be ween he onse o eb ile seizu es and c ossbi e (p=0.035; CVC =0.69; Table S6). We also ound
a endency owa ds co ela ion be ween o al numbe o assayed an iepilep ic d ugs and b uxism
(
p=0.065
; CVC =0.45), and a endency owa ds posi i e co ela ion be ween deg ee o seizu e con ol
and b uxism (p=0.065; CVC =0.54).
A e analyzing he gene ic a iables, we ound ha he size o he dele ion was co ela ed in a
s a is ically signi ican manne wi h he p esence o oligodon ia (p=0.009; CC =0.75); mean dele ion
size in indi iduals wi h oligodon ia was 8.1
±
3.9 Mb s. 2.6
±
0.6 Mb in hose wi hou oligodon ia.
A e dis ibu ing he dele ion sizes in o clus e s on he basis o clinical mani es a ions o WHS and a
p e ious classi ica ion [
3
] (<2.5 >,<5>,<8.5 >,<10 >,<12.5 >, and <13 >Mb), we ound s a is ically
signi ican co ela ion only when compa ing dele ions <5 Mb s. >5 Mb in ela ion o he p esence o
oligodon ia (p=0.001; Figu e 4).
Figu e 4.
p-a m o ch omosome-4 sc eening in Wol -Hi schho n synd ome pa ien s wi h oligodon ia.
Open squa e ed a ea is minimal egion associa ed wi h oligodon ia in ou coho (2.3–5.5 Mb).
Rema kably, MSX1 gene is placed a 4.85 Mb om elome e.
The e was also mode a e co ela ion be ween he size o he duplica ion and c ossbi e (p=0.047;
CC =0.56), and be ween size o duplica ion and b uxism (p=0.014; CC =0.44; Table S7).
4. Discussion
To ou knowledge, his is he i s s udy o da e o a case se ies o WHS ocused on o al indings and
i s co ela ion wi h he synd ome’s o he clinical and geno ypic cha ac e is ics. The esul s o ana omical
abno mali ies, clinical indings/como bidi ies, de elopmen abno mali ies, and epilepsy- ela ed and
gene ic-s udy da a p ima ily ag ee wi h hose ob ained in he Spanish-based WHS coho and we e
al eady discussed in p e ious publica ions [4,5,20].
In his s udy, he p e alence o down u ned co ne s o he mou h (1 o e e y 3 pa ien s) was
lowe han ha epo ed in p e ious publica ions, gi en ha a numbe o au ho s i a inding ha
o ms pa o he acial-pheno ype cha ac e is ic o WHS [
8
,
17
]. This disc epancy can be a ec ed by
a ious ac o s such as pheno ype se e i y, obse e subjec i i y, and he de ini ion o he inding,
which in some cases was iden i ied as “dis inc mou h” [
7
,
21
]. Down u ned co ne s o he mou h a e
also a equen inding among pa ien s wi h ch omosome 9q sub elome e dele ion synd ome (9qSTDS),
one o he mos common clinically ecognizable synd omes o sub elome e dele ions. Indi iduals wi h
J. Clin. Med. 2020,9, 3556 9 o 14
his synd ome also ha e o he cha ac e is ics simila o hose o pa ien s wi h WHS, such as g oss
mo o delay, congeni al hea de ec s, and epilepsy [22].
In he li e a u e, s udies indica ed ha abno mal enula a e an uncommon o al mani es a ion in
pa ien s wi h WHS [
18
], which has been epo ed in only an isola ed case [
6
,
23
]. Howe e , enulum
abno mali ies can be an ex emely use ul indica o in diagnosing a numbe o synd omic condi ions [
24
].
Fo example, enum hype plasia de ec ed in a numbe o he pa ien s o he p esen se ies was
conside ed an impo an diagnos ic inding in Ellis- an C e eld synd ome (caused by mu a ions in he
EVC1 and EVC2 genes loca ed on ch omosome 4p16), which also sha e o he o al mani es a ions wi h
WHS such as peg-shaped ee h, agenesis, oligodon ia, e up ion delay, and mic odon ia [25].
Mic ogna hia is conside ed one o he componen s o he cha ac e is ic acial pheno ype o
WHS [
7
,
17
], and ou esul s ag ee wi h hose in he li e a u e, which es ima e a p e alence o >50% [
18
].
Mic ogna hia is a common inding in some o he mos common ch omosome abno mali ies, such
as 18p dele ion [
26
]. In mic ogna hia, he ongue is posi ioned owa ds he back and p ojec ed in a
e og ade di ec ion owa ds he ha d pala e, causing a high-a ched pala e [
18
]. Cle lip/pala e appea s
in app oxima ely 25–50% o cases [
7
], a a e subs an ially highe han ha de ec ed in his se ies.
Conside ing ha isola ed cle pala e and high-a ched pala e migh ep esen he same en i y, hei
join p e alence would exceed 60% [
18
]; e en assuming his p oposal, his a e is su p isingly double
ha eco ded in he p esen se ies. Mic ogna hia, glossop osis, and espi a o y p oblems cons i u e
he Pie e Robin sequence o which isola ed cle pala e was subsequen ly added. Robin anomalad is
ela ed o a ious gene ic synd omes, especially S ickle synd ome [
27
], ollowed by T eache Collins
synd ome [
28
]. MSX1 mu a ions a e obse ed in he Pie e Robin sequence, and dele ion o an MSX1
agmen (4p16.3) loca ed in he WHS c i ical egion can cause a numbe o he synd ome’s acial
cha ac e is ics [29].
In 3 o e e y 4 pa ien s, den al e up ion was delayed. The i s published epo s o WHS
sugges ed ha delay in oo h de elopmen was a common inding in hese pa ien s [
30
]. Subsequen ly,
he p e alence o delayed den al e up ion in WHS was es ima ed o be 50% [
17
] and could be clinically
iden i ied by he pe sis ence o deciduous ee h [
16
,
17
]. Delayed oo h e up ion, oo h anomalies,
and den al agenesis a e also ypical indings in pa ien s wi h 22q11 dele ion synd ome who also
equen ly ha e congeni al hea mal o ma ions [
31
]. We ound peg-shaped ee h in 1 o e e y 4 pa ien s,
wi h he same p opo ion o mic odon ia, and almos 1 o e e y 5 pa ien s who had unde gone
adiog aphy was diagnosed wi h au odon ism. Al hough hese abno mali ies in oo h size and
shape we e men ioned in he li e a u e ega ding WHS, hei p e alence has no been speci ied [
7
,
17
],
and mos a ailable in o ma ion co esponds o indi idual case s udies [32–34].
In line wi h ou esul s, o he s udies sugges ed ha den al agenesis and oligodon ia a e common
indings in WHS [
2
,
19
]. Pos e io ee h a e mos o en a ec ed [
16
], especially pe manen second
p emola s [
19
]. Oligodon ia is a inding ha also a ec s app oxima ely hal o he pa ien s wi h
Williams synd ome (7q11.23 dele ion) [35].
Almos 80% o he pa ien s o he p esen se ies had gingi al in lamma ion (bleeding on p obing
o spon aneous). Al hough i was sugges ed ha pa ien s wi h WHS can exp ess some ype o
immunode iciency [
36
,
37
] ha migh po en ially comp omise gingi al heal h, i seems mo e plausible
o a ibu e his inding o de icien o al hygiene [
16
], which could also be exace ba ed in pa ien s
who ake hydan oins o con ol hei epilepsy. In a pa ien g oup wi h WHS who had unde gone an
o al-hygiene egimen unde hei gua dian’s con ol, he e was signi ican educ ion in he a e o
gingi al in lamma ion [34].
Re e ences ega ding malocclusions in WHS a e sca ce, and a <10% p e alence was es ima ed [
38
].
Howe e , mo e han hal o ou pa ien s we e Angle’s Class II, p esumably due o he mic ogna hia
(mandibula hypoplasia), mandibula e ogna hia (abno mal pos e io posi ioning o he mandible),
and o he p edisposing ac o s such as inge sucking. Mandibula e ogna hia is a common inding
in pa ien s wi h 1p36 dele ion synd ome— he mos common dele ion a e 22q11.2 dele ion [
39
]—and
in pa ien s wi h 5p dele ion synd ome (C i du cha synd ome) [
40
]. Malocclusion and c owding