Amelogenesis imperfecta among Israeli Jews and the description of a new type of local hypoplastic autosomal recessive amelogenesis imperfecta

Amelogenesis imperfecta among Israeli Jews and the description of a new type of local hypoplastic autosomal recessive amelogenesis imperfecta

Amelogenests imperfecta (Al) was detected in nine of 70,359 school children surveyed. a prevalence approximating 1 :8,000. Of these cases, eight were of the hypoplastjc type and one the snow-capped hypomaturation type Family studies demonstrated that hypoplastic Al was an autosomal dominant trait in two children and an autosomal recessive In six. Of three additional families referred to our clinic, two had autosomal recessive hypoplastic Al and one the hypocalctfied type, inherlted as an autosomal dominant trait. In four families, a new type of local hypoplastic autosomal recessive Al was observed, characterized by horizontal plttlng and grooving more pronounced in the middle third of the crowns of most teeth in both dentitions

T

wo types of amelogenesis imperfecta (Al) were described b> Weinmann and associates’ as autosomal dominant disorders: hereditary enamel hypocalcification and hereditary enamel hypoplasia. A later report further subdivided AI by clinical and histologic criteria.’ and as more information appeared in the literature it became evident that rrtnelog~tw.vi.s itttpclt:fidcrtt was a term describing hereditary defects of the enamel with a number of different modes of transmission and various phenotypes.,‘1~10The recent classification of Witkop and Sauk”’ describes the following types of AI based upon histologic and clinical features and modes of inheritance: H~~poplmtic~

1 -. ’ 3. -L. 5. 6.

Al.

Autosomal dominant Autosomal dominant Autosomal dominant Autosomal dominant Autosomal recessive Y-linked (dominant)

pitted hypopiastic Al local hypoplastic Al smooth hypoplactic Al rough hypoplastic AI rough AI (enamel agenesis) smooth hypoplastic AI

I Autosomal dominant h>l”“natttr;ltic)11-h4p”plast1~~ Al with taurodontiam -. ’ X-linked (recossi\/e) h~pomattlr~itioi~ ..1I .j. Autosomal recessive pigmented hypomaturation Al 1. Snow-capped teeth tautosomal dominant 1 H\~~~~t~~Ltl~~jfic~tI -1I

I Autosomal dominant hypocalcitiecl Ai -.’ Autosomal recessive hypocalcificd Al Witkop” I’ound the precalcnce ot a11t’ornls 01 AI to bc I : 14,000 to I : I6.000 in the United State\ The purpose 01‘ this paper is IO describe the results (11 ;I \urvcy of Al among Jcus in laracl and to report :I prcciousl! unclescribed form ot autosomai reccssi 1c local hypoplaslic Al encountered in tour families. MATERIALS

AND METHODS

Examination 01‘70.159 school children. aged 6 to IX j cars. receiving ticntal care from the Tel .4\ i\ and Jerusalem Municipalities. uas carried oul in cla\\IW~I~ with the aid of a mouth mirror and probe under natural light. The dentist zxamincr\ uerc trained b! lectures.

;I

printd

~rnples

of

\uggesti\t:

recorded an> C;W slightI> ot ,\I. The dclinition used for ,AI wa\ ot

hereditar)

clet’cct\

manual.

children:

and

group

examinations

of

the)

of

cn;unel

unas\ociatcd

\\,ith

gcn--

Amelogenesis imperfectu among Israeli Jekvs 149

LEGEND:

0

q q

Normal, female

0

Affected,

male

w

Repo’ted

to be affected

0

0

Not knowv

If affected

0

Age at exomlnation

Dead Consongulneous marriage

10 Ten moles and females *

f

Examined Probond

Edentulous

Fig. 2. Family I: Snow-cappedhypomaturation AI. Dentition of proband (M. H.) with “snow-capped” appearance.

Fig. 1. Legend to pedigrees.

Table I. Data on families of probands affected by amelogenesis imperfecta Parents of proband

Made of inheritance

Furnil!

No. HM. snow-capped

Unknown

HP,eruptiondefects Autosomal recessive andresorption HP, pitted Autosomal dominant HP. pitted Autosomal recessive HP, HP, HP. HP. HP. H(’

thin enamel local local local local

Autosomal Autosomal Autosomal Autosomal Autosomal Autosomal

dominant recessive recessive recessive recessive dominant

Origin

Consanguinity

Affected

Proband *

Affected

None None

Im Im, If

2f Im, If

3m, 5f 2m, 5f

Mother None Mother None

Im lm If 2f If If Im Im

If

Im, If Im, If If 2rl1, If If 3f Sm, Sf If

Iraq

First cousins

Afghanistan

Uncle-Niece

Yemen-Morocco Iraq Rumania

None First cousins None None None

Poland Poland Iraq Poland Poland

HM, Hypomaturarion. HP. Hypoplastic. HC, Hypocalcified. * Probands of familie\ I to 7 are from the survei-population.

Siblings

First cousins None

None None None

None

Mother

If lm If lm -

Norma/

m, Male. f, Female.

eralized defects.“. I” In Al, the defects of the enamel differ from those of environmental origin. In the latter, the enamel defects are limited to those portions of the crowns of those teeth developing at the time that the environmental etiology has its effect. and the condition is not familial. All recorded cases were reexamined by two of the authors (A. C. and E. E.), who eliminated a number of misdiagnosed cases demonstrating hypoplasia of environmental etiology and tetracycline staining. First-degree relatives (parents and siblings) of probands conclusively diagnosed as having AI were examined in their homes. Following preliminary analysis of family data, a more detailed family study was indicated, and all relatives that could be reached and examined were included. Also included in the family study were three families not part of the survey population, but whose probands were diagnosed in the consultation clinic of the Department of Pedodontics (Hebrew University-Hadassah Faculty of Dental Medicine). During the family visits, a detailed medical history was taken to eliminate environmental causes of disturbances of enamel formation or changes in color. Infor-

mation was collected on diseases or disturbances during pregnancy and the first 5 years of life, including tetracycline therapy, fluorosis, and enamel defects as a symptom of a recognized syndrome. Detailed family history and pedigree information were obtained from the parents or probands and reconfirmed by further questioning of family members when possible. RESULTS

AI was diagnosed in nine of the 70,359 children examined, a prevalence of 1: 8,000. Eight cases of AI were diagnosed as hypoplastic, and one corresponded to the snow-capped hypomaturation type.’ Among the probands there were two pairs of siblings, so that only seven families were represented. The family data are presented in Table I. The first seven families were derived from probands found in the survey, while families No. 8, 9, and 10 were detected through the Pedodontic Clinic. In two of these three, AI of a hypoplastic type was diagnosed, and in one a hypocalcified type was found. Fig. I presents the legend to the pedigrees of the families described. In all the families, observation of skin. hair. ex-

150 C110.wc4T et (11.

Family

1

Family

2

18 /15/n DS A5

tremitiea. dition

and medical

which

could

history

be associated

failed with

to revcal heritable

any condcfect~

of enamel. CASE REPORTS Family 1: Snow-capped

hypomaturation

Al

The prohand M;I\ ;I Ih-year-old ho> (R/1. H.) dcntition and teeth tupcring toa ard the inciwl ;trc’;I\. The hoclic~ of’ the teeth. particul;u-I\ the prrmolars. were hroMn and pitted. \\ith the

with ~~;ILXYI d occluul c:uilnch MCI inciwl ;~nci

MS

5 YS

Volume 47 Number 1

Fig. 7. Family 2: Autosomal recessive hypoplastic AI with eruption defects and resorption. Dentition of s-year-old brother (Y, S.). showing marked attrition and smooth surfacts of deciduous teeth. Enamel can be distinguished from the dentition on the worn surfaces of the lower molars.

Fig. 8. Family

Fig. 10. Family

3 pedigree

classical description in that the bodies of the teeth were pitted. As the condition in the parents was unknown, no detinite mode of inheritance could be determined. Family 2: Autosomal recessive hypoplastic with eruption defects and resorption

Fig. 9. Family 3: Autosomal recessive pitted hypoplastic Bite-wing radiograph of proband (Y. I,.). shouing diolucent areas in the enamel.

Al

The two probands in this family were a IS-year-old boy (A. S.) and a 13.year-old girl (M. S.). Their dentitions showed marked attrition. smooth surfaces. spacing between teeth. a ycllou -brown discoloration, and delayed eruption. .4 thin layer of enamel could be distinguished from dentin on some occlusal surfaces which had undergone attrition, On radiographic examination (Figs. 3 and 5). enamel was not evident. and in the girl localized radiolucent areas, suggestive of resorption of the crowns of unerupted teeth. were observed. The dentin and supportive tissues appeared normal. There was evtdencc of calcifications of the pulp in both erupted and unerupted teeth. Both parents were Jews born in Afghanistan. related as uncle and niece (Fiy. h). Their dentition showed no evidence

AI. ra-

3 pedigree

of disturbances in enamel formation. Of nine siblings, a girl aped I8 years (D. S.) and a boy aged 5 years (Y. S.) (Fig. 7) showed tindings similar to those observed in the probands. The numerous other family members (Fig. 6) were tither found upon examination or reported to be unaffected. The clinical and radiographic findings and the pattern of inheritance in this family are compatible with an autosomal recessive hypoplastic AI with eruption defects and resorption reported by Witkop and Sauk,” a rare condition seen by them in only two families. Family 3: Autosomal

dominant

pitted hypoplastic

Al

The proband was a l3-year-old boy (A. K.). All teeth had pitting of the whole surface. The upper anterior teeth were Stained brown. and caries was present in the upper lateral incisors. At 7 years of age. the proband had had radiographs taken in which the hypoplastic changes could be clearly distinguished in both the primary and permanent dentition. The radiopacity of the enamel contrasted normally with that of the dentin,

Fig. 11. Family tapered

5: Autosomal

touard

the incisal

dominant

hqpoplaatic

or occlu~l

wr-f’ace.

Al

The

Fig. 12. Farnil) 5: .Autowmal dominant hypoplahtic ia! CI’ 01. enamel with nomal opacit?

(thin

enamel).

Teeth

of proh;tnd

enamel

wrf’acc

i\ \~noc~~h and hard

AI (thin

cnamcl

I. Radiograph

IS.

H I ;II~~ \m;til

01’ prohand

tS

MCI

H. I. \ho\\

\ng .I

thin

16 f13 y.l3.Fig. 13. Family Both

parents

can origin uas

were

not consanguineous.

remaining

in her mouth

the proband. siblings

The

primav

teeth

the maternal were as AI

I\;IS affected.

pitting

dominant

from

(Fig.

to that seen in her

ing.

the mother uncle.

~!pc.“,

Nere

indicated

that

and his tw’o wns

were

farnil)

memhe~-

The

proband

had hard rough

” transmitted

The nodular of pits with

appearance

and proove\.

degree

in the lower crowns.

deficiencies (Fig. The

in

pitted hypoplastic

was a 1%year-old and nodular has These incisors.

hog

surfaces

b!

an

ShoMed

localized

radiolucent

Al M hose

teeth

broa,n

of an irregular

patterr

pt-esent

incisor\

e~~dence areas

to a lesser

in Ii-q.

w crc

ohviou\

ihc p,rrcnt\

and \Ih-

\tatcd

that no additional

di\turhancc

v,crc

in tooth

covered

The

probuntl. between

occlusal Periapical

ap-

first

cousin\

(Fig.

dominant

girl

I+ hi&

(S

and hard.

M ithout

yho\vctl

( IT1~. I7 1

one

;I\ .I

or \c\-

marriqc

01

Al (thin enamel)

f3 J. 111an1f’csted \\I& toward

polntcd: ;I thin

ho)

c mhcrltanct‘

tapcrcd

were

and

by an ‘ILI-

.Iuto\omal

hypoplastic

Ihc cusps

radiograph\ opaclt!

rrce\\i\

;I I i-\?a~--old

smooth

\\ lth onI\ mutatic~n.

the conwnylncou\

autowmal

type,

.Al of Il’ithop

to hc dct~‘m~~nt‘d

hIthough.

the teeth.

wrfac~~~

v,ere

farnil)

be cxcludcd.

\ugFcxt\

spacing

h! popla\tic

01’ ;I nw

Family 5: Autosomal

teeth

enamel

in thi\

rece~~i~ c gent. cannot

as ;I1 01 (I h! poplast~c

the pitted

the posvhilit>

in

the

N ;I\ diagnosed

tosomal

normal JCU \ born

an!

\uhject.

of the enamel

9). pal-ents.

lormatlon sihl ing\


and the p;nent\

resenihling

the parent\

stained

\\crc

The upper

Radiographs

I..).

and were

the rc\ult findings

(1’.

01 cxwpcration.

had

The condition somewhat

linked,

recessive

of lack e\camincd.

Rae.!’ hut appca~-\

Eva\ diapnowd

gene.

Family 4: Autosomal

III cn;m~cl

The TV 11 cider

unaffected

Because lings

no di\rurbanw

‘r\ as one of three children.

pearance

8). The condition

hypoplastic

other

aged i. wa+ affected.

teeth 4io~~ed

The prohand

the teeth

Of’ the three

and groo\

IO). Their

of Moroc-

The marriage

similar

a maternal

affected

of’ the pitted,

pitting

sister.

obtained

grandmother,

similarI>

autosomal

The mother

a younger

histoE

the father descent.

was not affected.

showing

The family

in Israel.

of Yemenite showing

father

examined.

5 ped~~rcc

Jews born

and the mother

S.B.

the inci4

the wlt‘ace\

dwoloratw

OI01. Ihc

(Fig.

I 1 1.

1x1 cl- cl< I’II~~IICI

v ~th

Amelogenesis impe@cta among Isrcleli Jeu’s

Fig. 15. Farnil)

153

7 pedigree

(Fig. 1.7). Both had full dentures. The mother stated that she had had teeth \imilat to those of her daughter. Of two sisters, one (Y. B.) \\as Gmilarl! affected. Radiographs taken of Y. B. at age I I \hoM that teeth of her primary dentition were similarly affcctccl. Because of lack of cooperation, no further information about thi\ t’un~ly could be obtained. Six months later. it C;IIIIO to the investigators’ attention that another famil! origmating from Rumania had presented with similar dental tinding in the mother and her daughter. Further questions revealed that the mothers of both families were relatives, but the exact nature of the relationship could not be obtained. The condition differed from auto\omal dominant smooth hypoplastic .4l described in the literature,!‘. I” in that there was no delay or failure of eruption and resorption of teeth in the alveoli, or Ggna of pulpal calcifications. Without radiographs. thr clinical appearance of a smooth, white, hard SUP face might easil) lead to a misdiagnosis of disturbance in the morpholog) of the teeth. The condition \\ as diagnosed as hypoplastic type of AI with thin enamel. tranjmttted as an autosomal dominant condition.

were mainly in the middle third of the buccal surfaces of the crowns. The lower incisors were least affected. and the canines and premolars were most affected. The surface changes did not follow age patterns observed in hypoplasia 01 environmental origin. No attrition was observed. and the color was normal. The parents were not relatives; their teeth were normal. Of the two other siblings, a brother, aged 13. was similarly affected. All the other family members were found OI- reported to be unaffected (Fig. IS). The condition was diagnosed as Al resembling the local hypoplastic Al’, i. !‘. I” but differing in that in this family it seemed to be transmitted by an autosomal recessive gene.

Family 6: Autosomal

Family 8: Autosomal

recessive,

local hypoplastic

Al

The two probandc in this family were girls aged 14 and 8. The teeth of the prcjbands showed pitting, horizontal grooving. and light-brou n discoloration of varying degrees. These deticiencie> \\ere more obvious in the middle of the buccal \urfacrs of the cro\+ns. In both probands, the lower permanent incisor\ were least affected. In the X-year-old proband, the primat? cuspid\ and molars present also had pitting and irregularities of the enamel. The surface changes did not follow age patterns observed in hypoplasia of environmental origin. Na excessi\ e attrition was observed. The father mas born in Israel. and the mother in England. Roth were of Polish-Jewish ancestry and unrelated. Their teeth appeared noI-mal. Two male siblings were unaffected. A paternal aunt and ;I maternal uncle with his three children iserr txmilnecl and found to be unaffected (Fig. 14). The clinical cc)ndition resembled the local hypoplastic Al described pre\ iousl! . ~‘.‘. “. I” but the genetic transmission seems to he autobonxtl recessive. Family 7: Autosomal

recessive

local hypoplastic

Al

The proband LL;IY a l&gear-old girl whose teeth showed ~rface pitting and qoving of varying degrees. The defects

Fig. 16. Family 8: Autosomal recessive local hypoplastic Al. Mixed dentition of proband (L. A.). showing horizontall) pitted and rough surfaces. Caries is advanced in upper incisors and molars.

recessive

local hypoplastic

Al

The proband (L. A.), a girl aged IO. had mixed dentition. All teeth were dark yellow. with the surface horizontally pitted and rough. The pattern of the defects did not correspond to a specific time of tooth formation. Caries had resulted in severe loss of tooth material in some teeth (Fig. 16). The parents, Jews born in Iraq. were first cousin5 (Fig. 17). Their dentitions showed no evidence of enamel defects. Of the four other sisters, one, a Z-year-old girl. had Al with yellow-brown discoloration of all deciduous teeth present. the surfaces of which were uneven. Fort)-nine farnil! members were examined; only the above-mentioned sisters were affected. The condition was diagnosed as Al resembling the local hypoplastic type,“ i. !’ seeminglv _ transmitted 3s an itutosomal recessive trait. Family 9: Autosomal

recessive

local hypoplastic

Al

The proband (M. I.). a II-year-old boy, had a mixed dentition colored light yellow. The surfaces of all teeth were rough, with horizontal grooving, pitting, and ridges. more pronounced in the middle third of the crowns of all teeth. The lower incisors were less affected but showed pitting and xtaining in the ginpival half of the crown? (Fig. IX). The pattern of

Family

8

LA

Fig. 18. Farnil) 9: Autosomal reccsji\,e local h>popiastic .AI. Mixed tientltlon of’prohand (M I. 1, \\ith horizontal pitting and grooving affecting all teeth. Fig. 19. Farnil! 0: Autrrsomnl reccs\i\ e local h!poplasrlc AI, Bite-\\ in,~7rxlwyq3~~ III prohand (;bl. I.) tahen at age 9. showing thinning of the enamel 111the middle 01‘ the proximal wtl’xex of holh primal-! and perm;ment 11101;11~ Family

Other tarnil! incmbers c4ammcd (Fig. 3)) uerc‘ tound to he unat’fwted The condition in the prohand and the afl’cc~d Ghling ~a\ diagnosed as Al rewmbling the Ioc;~l hypopla4c t,\,,c,‘. T !I prohahl! tranwiittcd as an auto\omal recessi\ c trait: ho\+oet-. Vlinhed inheritance c‘annot bc ruled out.

9

Family

10: Autosomal

dominant

hypocalcified

Al

Fig. 20. Farnil? 9 pcdig~we

the su~fxx del’ec(\ ~3s not related to qc. ;I\ I\ wcn ni CII\ ironmental disturbances. 7 I c) showed ;I normal Bitt-wing radiograph\ taken at a>t contrast between enamel and dentm. hut v,ith thlnnlng of the enamel. mainly c‘\ ident in the middle of the crw II\ of both primal and permanent molar\ (Fig. IO). The parents. JCM s horn in Poland, ur‘rc not I-c~;I~I~L’\. ‘1he11 &ntition\ wre normal, All I I \ihling\ wre examinctl: one brother. aged 1.3. w;i\ similarly aft’ccted. FOLII- other sihlinF\ \howed mild disturbances of the enamel of indib idual teeth. hut LIdefinite diagnosi\ of Al could not he mado in their C;IW\

The radiograph\ \howcci cv~icnce 01 thin ~‘namcl. prewnt mainI\ in thtz intcrproxinial and cervical ;uxx\. The parent\. Jc‘\v\ both horn in I\I-xl from Polish ance\tr!. MCI-C noi lKiati\ c\. The tnothcr had lull crown covzrasc 01 all her twth and \+a ;IMNC that \hc’ wtfered t’rom AI. a had her’ l’ather. Kadiographs of the mother’\ tt. X. J dcntitlon at a;c 17 hhov,cd ,I moth-eaten qpearancc 01’ the en:~mcl. Roth Iov.t’r cuspid\. the lover Icft 1;1ta11 incisor. and the upper left cuspid wc‘rc

Volume 47 Number?

Amelogenesis imperfecta among lsraeliJews 155

Fig. 21. Family 10: Autosomal dominant hypocalcified Al. All the primary teeth of -I-year-old proband (S. N.) show abnormal texture and areas denuded of enamel toward incisal and occlusal surfaces. Advanced decay is evident in the upper incisors. Fig. 22. Family IO: Autosomal dominant hypocalcified AI. Radiograph of the mother’s dentition (E. N.) taken at age 17, showing moth-eaten appearance of the enamel of the erupted teeth. Fig. 23. Family IO: Autosomal dominant hypocalcified AI. A maternal uncle (A. L.) with severe staining and irregular surfaces of all teeth. unempted. A distinct enamel layer could be distinguished on the unerupted cuspids (Fig. 22). The father and the 9-year-old sister were not affected. The mother’s brother (A. L.) (Fig. 23) and his daughter- were also affected. Information given by the mother indicated that members of a branch of the family living abroad were similarly affected (Fig. 34). The condition in this family was AI of the hypocalcified type.‘, ‘. !’ transmitted as an autosomal dominant trait.

In the 10 families studied, 26 individuals (12 probands and 14 relatives) were diagnosed as having AI of either the hypoplastic, hypocalcified. or snow-capped hypomaturation type. In six of the families, the findings differ from those described in the classification of Witkop and Sauk.“’ In family 4, the pitted hypoplastic AI was most probably inherited as an autosomal recessive trait. In family 5 (autosomal dominant hypoplastic AI with smooth thin enamel), the clinical findings differed from those described in autosomal dominant smooth hypoplastic AI and in X-linked dominant smooth

Family

10

Fig. 24. Family IO pedigree.

hypoplastic AI.“’ In families 6 to 9, the condition resembled the local hypoplastic type,“, “’ but was inherited in these families as an autosomal recessive trait. Two methods were used to test these four families for compatibility with autosomal recessive inheritance.

DISCUSSION