American Journal of Medical Genetics 30:459-471(1988)

IS THERE A F'RAGILE(X) NEGATIVE MARTIN-BELL SYNDROME?

A. Thode, S. Laing, M.W. Partington, G. Turner.

Department of Medical Genetics (AT, MWP, GT) and Cytogenetics Unit (SL) , Prince of Wales Children's Hospital, Randwick, New South Wales, Australia

ABSTRACT

During the course of the preventative screening program for the fra(X) syndrome, we identified 32 men with the phenotype but who were fra(X) negative. the full criteria, so we were unable to confirm the existence of the fra(X) negative Martin-Bell syndrome. families previously thought to have the fra(X> negative Martin-Bell syndrome were also reviewed. a concrete diagnosis of the fra(X) negative Martin-Bell syndrome.

These were reviewed and none fitted

The literature and 4

We were unable to make

INTRODUCTION

After Lubs [1969] reported the marker X chromosome and Harvey et a1 [1977] appreciated its diagnostic significance, it has been questioned whether the Martin-Bell syndrome [MBS] without the fra(X) exists. Several families with X-linked mental retardation [XLMR] in which the affected males apparently had the MBS without fra(X) in their lymphocytes [Jennings et al, 1980; Herbst et al, 1981; Howard-Peebles et al, 19791 have been published. However, cytogenetic techniques to demonstrate the fra(X) are constantly being refined. for the fra(X) syndrome among the intellectually handicapped in

During a screening program

Keywords: Martin-Bell syndrome, mental retardation, X-linkage.

Fragile site (X)(q27.3), fragile(X) syndrome,

Address reprint requests to Dr. A. Thode, Department of Medical Genetics, Prince of Wales Children's Hospital, High Street, Randwick NSW 2031, Australia. 0 1988 Alan R. Lw, he.

460 Thodeetal.

New South Wales we decided to look for the MB phenotype without the fra(X). We also reviewed 4 families that had been studied previously and thought to show the clinical picture of the MBS although the affected males did not have the fra(X).

MATERIALS AND METHODS

In 1986, during the screening program for the fra(X) syndrome in New South Wales [Turner et al, 19861, 651 adult males were seen and tested; of them 57 were shown to be fra(X) positive and to have the MBS. Thirty-two of the remaining 594 were expected by the examining physician to be positive after a brief physical examination. This did not include measurement of testicular size since this was inappropriate in the circumstances in which the screening examination took place. None of those 32 had the fra(X) demonstrable in their lymphocytes. each was revisited and a more detailed examination was carried out with attention to facial structure, body habitus and personality. A short, plastic ruler was used to measure ear height and testicular length (L) and width (W) with which tesgicular volume was calculated according to the formula LxW xd'6 [Cantu et al, 19761. define macro-orchidism [Partington, 19841. We endeavoured to contact the families of these males looking for evidence of X-linked intellectual handicap.

Subsequently,

A lower limit of 30 ml was used to

Blood for chromosome analysis was set up in triplicate in Iscoves Low Folate medium made to recommended specigications with 5% fetal calf serum. and harvested by standard procedures. metaphases was scored for the fra(X) on each patient and the nature of any fragile site confirmed by G banding.

Cultures were incubated at 37 C for 4 days A minimum of 200

RESULT

Blood was collected for fra(X) testing from only 5 of the 32 men; they ranged in age from 20 to 75 years. or normal testicular size, and no other gross manifestations of MBS .

The rest had small

Fra(X) Negative M i - B e l l Syndrome 461

The 5 men tested will be discussed (Table I).

Table I. Phenotype of the 5 Men Retested for the Fragile X

~~~~~

Manifestations

Patients

1 2 3 4 5

MB facial appearance

Auricular height (mm)

Head circumference (cm)

Eunuchoid habitus

Mean testicular volume a

Degree of mental retardation b

Family history of mental retardation

% fra(X)(q27.3)

+ + + + + 85 79 75 75 69

57 59 60 53.5 61

+ 0 0 0 0

49.5 40 30 42.5 32.5

3 3 2 3 3

+ 0 + 0 0

5 0 0 0 0

a b Standard levels of mental retardation* + present 0 absent

Mean testicular size = R + L/2 in ml.

Patient 1

JM (Fig. 1) was a 55 year old man with a head circumference

His ears were 85 mm in height, he (OFC) of 57 cm and height of 171 cm. His facial characteristics were consistent with the MBS. had soft skin, a eunuchoid habitus and macro-orchidism. From his guardian we were told that he had an older brother with intellectual handicap.

* 1 = borderline; 2 = mild; 3 = moderate; 4 = severe;5 = profound

Other relatives were visited and

462 Thodeet al.

a pedigree constructed (Fig. 2). of his lymphocytes upon repeat testing.

This man had the fra(X) in 5%

Fig. 1. JM

Fig. 2. Pedigree of JM. Solid left side of symbols: MR; solid right side of symbols: of symbols:

fra(X) positive; line across right side tested negative for fra(X)(q27.3)

F r a o Negative Martin-BeU Syndrome 463

Patient 2

FJ? (Fig. 3) was a 69 year old man with a OFC of 59 cm and a height of 164 cm. His facial appearance was consistent with the MB phenotype, and he had a friendly nature and macro-orchidism. There was no family history of intellectual handicap, and he was fra(X) negative. From photographs it was obvious that F.F., his father and paternal uncles all had a MBS-like facial appearance with large protruding ears: this was the family phenotype.

Fig. 3. FF

Patient 3

PO (Fig. 4 ) was a 39 year old man with a OFC of 60 cm and a height of 174 cm. He had mild intellectual handicap, a solid physique, large forehead and unilateral macro-orchidism. A family history of intellectual handicap was ascertained: 2 affected nephews were microcephalic and without the MB phenotype. He was fra(X) negative.

Patient 4

CM (Fig. 5) was a 53 year old man with a OFC of 53.5 cm and height of 170 cm. lived in an institution. with the MB phenotype; he had a highly arched palate and macro-orchidism. found that he was normal until the age 2 years when he had

He had moderate intellectual handicap and His facial appearance was consistent

On contacting the family of this man it was

464 Thodeetal.

bacterial meningitis. intellectual handicap, and he was fra(X) negative.

There was no family history of

Fig. 4 . PO

Fig. 5. CM

Patient: 5

SP (Fig. 6) was a 26 year old man with a OFC of 61 cm and a height of 182 cm. 69 mm in height and not protruding.

He had a long face but his ears were only He had unilateral

Fra(X) Negative Martin-Bell Syndrome 465

macro-orchidism and in addition he had right ventricular outflow tract obstruction. He was a single child, fra(X) negative, and there was no history of intellectual handicap in his mother's family .

Fig. 6 . SP

We reviewed 4 families (studied between 1979 and 1981) with X-linked intellectual handicap in which affected males were thought to have the fra(X) syndrome although they did not have the fra(X).

Family S [Fig. 71 had affected males in 3 generations. The probands, 3 brothers who attended a slow learners class in a normal high school, have remained at home since leaving school and are seeking open employment as unskilled labour. had seizures in the first 2 years of life but good health thereafter. They had a normal head circumference, testicular volumes between 25 and 30 ml, no minor anomalies, and their facial characteristics were not consistent with the MB phenotype. Two have tested negative for the fra(X). affected males in the family have married, fathered children and did factory work.

They each

Two other similarly

Family B [Fig. 81 had affected males in 3 generations. The proband, born prematurely at 33 weeks of gestation with a birth weight of 2126 g had physiotherapy for spacticity in his lower limbs in the first 18 months of life, development.

He had delayed psychomotor He attended a child guidance school classed as an

466 Thodeet al.

emotionally disturbed child which was thought to have been due to maltreatment from an alcoholic father. On review, he lived independently with his wife who was expecting their first child. He was working in a factory but needed help with budgeting and managing his money. He was 180 cm tall with a OFC of 56 cm and a normal appearance. He had a long face with a large forehead but a small jaw and normal size ears. He did not have macro-orchidism and tested negative for the fra(X). His younger brother had delayed psychomotor development but to a lesser extent; he attended the same school but died at age 6 years in a motor vehicle accident. A maternal uncle attended a slow learners class but had been in open employment and living alone, although he needed help with his finances. Two similarly affected males in another branch of this family were not considered to be at all handicapped by their parents.

El I

II

m N

V sss4’ ’ ’ Fig. 7. Pedigree of family S: Solid left side of symbols: MR; shaded: dull intelligence.

I

II

rn Iv

Q T i & 3 14 15 16 17

t Fig. 8. Pedigree of family B. Solid left side of symbols: MR.

Fra(X) Negative Martin-Bell Syndrome 467

In family G [Fig.9] the probands were a pair of brothers first seen when 26 and 28 years old, and on review when 43 and 45 years old. the normal range, and normal testicular volumes. The older brother was moderately intellectually handicapped, attended a sheltered workshop and had a normal appearance. brother was severely handicapped, in an institution and had unacceptable social behaviour. posterior hairline and no manifestations of the MB phenotype. Both tested negative for the fra(X>. A maternal uncle had low mild intellectual handicap and an appearance not suggestive of the MB syndrome.

They both had height, weight and OFC measurements in

The younger

He had a flat occiput with a low

[GI I

II

m rv

Fig. 9. Pedigree of family G. Solid left side of symbols; MR.

In family R [Fig. 101 the proband was a 12 year old boy with moderate intellectual handicap. micrognathia and a high palate. for age but he had narrowness of both temporal regions. His ears were normal in height and mildly protruding. macro-orchidism and tested negative for the fra(X). There were 3 intellectually handicapped male maternal cousins; on one no information was found, another was profoundly handicapped after a motor vehicle accident and the third was a moderately handicapped boy who attended a special school in South Australia. medical officer wrote that he had a normal facial appearance with a broad forehead, a flat occiput and brachycephaly. His testes were normal. The proband's uncle was a 40 year old moderately intellectually handicapped man without the MB phenotype and with normal testicular volumes. He tested negative for the fra(X).

He had a large forehead, His OFC was on the 25th centile

He did not have

His

468 Thodeetal.

0' lllltllllll OlAClOSlS t ItRlllYlllDW

41 x x v

Fig. 10. Pedigree of family R. Solid left side of symbols; M R .

DISCUSSION

We tried to find families with the MBS by reviewing 32 fra(X) negative "good starters" from the New South Wales screening program for the fra(X) syndrome. families with X-linked intellectual handicap where affected males were previously thought to have the MB phenotype but tested fra(X) negative. and the diagnosis was excluded if they did not have the MB phenotype including macro-orchidism.

We also reviewed 4

All affected males were personally examined,

Of 32 intellectually handicapped males thought "good starters" only 5 had the ME3 phenotype sufficient to warrant testing. one had bacterial meningitis when young. (3rd centile), may reflect reduced growth from brain damage and his macro-orchidism may have been a consequence of this. Fryns et a1 [1986] reported on 3 fra(X) negative males with acquired lesions of the central nervous system who had macro-orchidism and facial characteristics similar to those found in fra(X) syndrome males. intellectual handicap but his 2 affected nephews had microcephaly. MB phenotype but no family history of intellectual handicap. of these men shared the MB facial appearance with many paternal relatives all of whom were very intelligent.

Of these one was positive fra(X). Of the other 4 men, His OFC of 53.5 cm,

Another male had a family history of X-linked

The other 2 males had some characteristics of the One

None of the individuals in the 4 families we reviewed with X-linked intellectual handicap had the MB syndrome; the affected male relatives did not have the characteristic phenotype

FraQ) Negative Martin-Bell Syndrome 469

involving the face, ears and testes. In 2 of the families, the intellectual handicap was less of a concern to the affected males as adults than when they were school children.

Failing to identify the fra(X) negative MBS ourselves we conducted a critical review of the literature. Of the 4 families with X-linked intellectual handicap reported by Howard-Peebles et a1 [1979] one had the fra(X) syndrome. There was insufficient information and no photographs of affected males from 2 families to determine whether they had the MB phenotype, although it was noted that an affected male in each family did not have macro-orchidism. fourth family did not show the facial characteristics of the MB phenotype.

A photograph of an affected male from the

Herbst et a1 [1981] present 6 families; 3 with the fra(X) syndrome. one intellectually handicapped male was tested. year old boy who, from his photograph, had a flat mid-third of face and micrognathia. He also had microcephaly at the age of 30 months although at 11 years his head circumference was "above the lower limit of the normal range". male was below the 3rd centile in height and the photographs of 2 other affected males do not represent the MB phenotype, although they had large "lop-ears". There were no specific details of the third family, M, although a photograph of one affected male was consistent with the MB phenotype. In these 3 families only one affected male from family M had testicular volumes above 30 ml.

Jacobs et a1 [1980] reported 7 families with X-linked

Of the 3 families without the fra(X), in family J only He was an 11

In family DJ, one affected

intellectual handicap, for the fra(X) and the the seventh family was that previously reported by Renpenning et a1 [1962] and Fox et at [1980] in which the intellectually handicapped males do not have the MB phenotype.

Six of these were found to be positive

Jennings et a1 [1980] presented individuals in 3 pedigrees with X-linked intellectual handicap. syndrome. whom were examined and had profound mental retardation, deficient speech, an OFC above the 90th centile, large ears, prognathism and macro-orchidism. However, neither expressed the fra(X) in 400 metaphases. negative for the fra(X> on testing in 1987 we would make the diagnosis of the fra(X) negative MBS.

Two had the fra(X) In the third family there were 5 affected males, 2 of

If the affected males in this family were still

Fishburn et a1 [1983] reported individuals in 6 pedigrees with mental retardation without the fra(X). been found to have the fra(X) syndrome. Another was recently reviewed by a neurologist and a geneticist; the affected males were mute, had joint contractures and a neuropathy and did not

One family has since

470 Thodeet al.

have the ME3 phenotype. handicapped males had been diagnosed, so X-linkage has not been established.

In 3 families, no further intellectually

The sixth family had not been reviewed.

Thus, if the fra(X) negative MBS exists it is much less common than the fra(X) positive MBS. From our experience it is worth repeating the cytogenetic analysis on an intellectually handicapped male with the ME3 phenotype if he is found to have a family history of mental retardation and we also suggest testing other intellectually handicapped family members.

Macro-orchidism has not been found in all fra(X) syndrome males, although it is present in more than 80%, yet we used this as a decisive factor in determining who to retest of 32 intellectually handicapped "good starter" males. However, of the 27 fully examined but not retested, independent of testicular size, there was not a male who we felt reasonably confident would have the fra(X) syndrome if he was retested. The only male of whom we were so confident as to bleed a third time or consider skin biopsy was the one male who did test positive for the fra(X).

In conclusion, we could not find any evidence for the existance of the fra(X) negative MBS.

REFERENCES

Cantu JM, Scaglia HE, Medina M et a1 (1976): congenital normofunctional testicular hyperplasia and mental deficiency. Hum Genet 33:23-33.

The diagnosis and frequency of X-linked conditions in a cohort of moderately retarded males with affected brothers. Am J Med Genet 14:713-724.

Fox P, Fox D, Gerrard JW (1980): Renpenning revisited.

Fryns J-P, Dereymaeker A , Hoefnagels M, Volcke P, Van den Berghe H (1986): megalotestes in fra(X)-negative patients with acquired lesions of the central nervous system. Am J Med Genet

Inherited

Fishburn J, Turner G, Daniel A, Brookwell R (1983):

X-linked mental retardation: Am J Med Genet 7:491-495.

Partial fra(X) phenotype with

23:213-219. Harvey J, Judge C, Wiener S (1977): Familial X-linked mental

retardation with an X chromosome abnormality. J Med Genet 14:46-50.

Herbst DS, Dunn HG, Dill FJ, Kalousek DK, Kryanivsk LW (1981): Further delineation of X-linked mental retardation. Hum Genet 58:366-372.

X-linked mental retardation, verbal disability and marker X chromosomes.

Howard-Peebles PN, Stoddard GR, Mims MG (1979): Familial

Am J Hum Genet 31:214-222.

ha) Negative Martin-Bell Syndrome 471

Jacobs PA, Glover TW, Mayer M, Fox P, Gerrard JW, Dunn HG, Herbst DS (1980): X-linked mental retardation: A study of 7 families. Am J Med Genet 7:471-489.

and chromosomal abnormalities in X-linked mental retardation (Martin Bell or Renpenning syndrome). Genet 7:417-432.

Jennings M, Hall JG, Hoehn H (1980): Significance of phenotypic

Am J Med

Lubs HA (1969):

Partington MW (1984): The fragile X syndrome 11: Preliminary

A marker X chromosome. Am J Med Genet 21:231-244.

data on growth and development in males. Am J Med Genet 17~175-194.

Renpenning H, Gerrard JW, Zaleski WA, Tabata T (1962): Familial sex-linked mental retardation. Can Med Assoc J 87:954-956.

Turner G, Robinson H, Laing S, Purvis-Smith S (1986): Preventive screening for the fragile X syndrome. J Med 315:607-609.

N Engl

Received for publication September 14, 1987; revision received November 2, 1987.