Different Phenotypic Expression in Relatives WithFabry Disease Caused by a W226X Mutation

I.E. Knol,1* M.G.E.M. Ausems,1 D. Lindhout,2 O.P. van Diggelen,2 H. Verwey,3 J. Davies,4J.K. Ploos van Amstel,1 and B.T. Poll-The5

1Clinical Genetics Center Utrecht, Utrecht, The Netherlands2Department of Clinical Genetics, Erasmus University, Rotterdam, The Netherlands3Oosterschelde Hospital, Goes, The Netherlands4Division of Biochemistry and Genetics, Institute of Child Health, University of London, London, United Kingdom5University Children’s Hospital ‘‘Het Wilhelmina Kinderziekenhuis,’’ Utrecht, The Netherlands

Two male relatives with Fabry disease pre-sented striking differences in clinical symp-toms and age of onset. The propositus hadretarded statural growth and skeletal dys-plasia while his nephew suffered mainlyfrom aggravating acroparesthesia and ce-liac disease. Fabry disease is an X-linked in-born error of glycosphingolipid metabolismresulting from deficient activity of the lyso-somal hydrolase a-galactosidase A (a-Gal A)enzyme. The a-Gal A gene is located atXq22.1. Efforts to establish genotype-pheno-type correlations have been limited becausemost patients have private mutations. Inprevious clinical studies performed in fami-lies with Fabry disease, marked differencesin phenotype are described between af-fected relatives. This family also demon-strates the difficulty in predicting the clini-cal phenotype in patients and relatives withthe same a-Gal A mutation. Furthermore, inthe absence of a family history, the diagno-sis may be easily missed. Am. J. Med. Genet.82:436–439, 1999. © 1999 Wiley-Liss, Inc.

KEY WORDS: Fabry disease; a-galactosi-dase A enzyme; genotype-phenotype correlation; gas-tro-intestinal manifestations

INTRODUCTION

The a-Gal A gene was localized within band Xq22.1and sequenced [Bishop et al., 1988]. At least 110 generearrangements, splice-junction defects, and point mu-tations have been identified causing the classical and

milder-variant Fabry phenotypes. Most mutationshave been confined to single families, indicating highgenetic heterogeneity [Eng and Desnick, 1994; Davieset al., 1996]. The molecular lesion fails to predict thephenotype. Determination of the tertiary structure ofthe enzyme may provide a better understanding of mu-tational effects [Davies et al., 1994]. So far, most stud-ies to establish genotype-phenotype correlations havebeen done using clinical information from unrelatedpatients with the same genotype, i.e., the same a-Gal Amutation [Eng et al., 1994]. In this paper we describethe clinical phenotype in related patients with com-plete a-Gal A deficiency. The propositus, diagnosed atage 18 years, had severe growth retardation and skel-etal dysplasia. The main symptoms of his nephew wereacroparesthesia and celiac disease. The present familyillustrates the importance of studying differences inclinical presentation from related patients.

CLINICAL REPORTS AND RESULTSCase 1

The propositus (Fig. 1, III-2) was referred at age 18years for evaluation of short stature and delayed pu-berty. Initially his statural growth was at the 90th cen-tile, declined to the 50th centile at 10 years, and sub-sequently under the 3rd centile at 18 years. Endocrinefindings included normal values of growth hormone.From 6 years on, an increasing disproportion in growthbetween trunk and limbs was noted. After a long walkor after a short night of sleep he complained of pares-thesia in his feet. During childhood he had recurrentotitis and bronchitis and periods of hypohydrosis. Byhistory his facial appearance had coarsened in time.Since early childhood he has been known to have asmall ventricular septal defect (VSD) without dynamicconsequences.

At age 18 years his height was 163.5 cm (2.5 cm, <3rd centile) and weight 38 kg (5 kg, < 3rd centile). Hehad a broad neurocranium with short neck and slightprognathism, a short and broad chest with retractedshoulders, high small scapulae, dorsal kyphosis, flexedcontractures of the elbows, and relatively slender fin-gers and toes. Angiokeratoma could not be observed.

*Correspondence to: Irma E. Knol, MD, Clinical Genetics Cen-ter, Utrecht, P.O. Box 18009, 3501 CA The Netherlands. E-mail:knol@pobox.accu.uu.nl

Received 14 July 1998; Accepted 10 November 1998

American Journal of Medical Genetics 82:436–439 (1999)

© 1999 Wiley-Liss, Inc.

Radiographs showed generalized low bone density,thoracic platyspondyly, and several transverse denselines in the long bones suggestive of periods of meta-bolic derangements in the past. His bone age was 5-6years delayed in maturation according to Greulich andPyle standards. Because of glycolipid-like spots in thecornea, Fabry disease was considered in the differen-tial diagnosis. Severe deficiency of the a-Gal A activitywas demonstrated in leukocytes, confirming the diag-nosis (Table I).

The mother of the propositus (Fig. 1, II-1) had com-plaints of hypersensitivity to cold temperature and ac-roparesthesia triggered by fever. She had an interme-diate level of a-Gal A activity, confirming carriership(Table I). The brother of the patient (Fig. 1, III-3) hadnormal a-Gal A activity. The sister (Fig. 1, III-1) had anormal level of enzymatic activity. A W226X mutationin exon 5 of the a-Gal A gene was identified in thepropositus and his mother. The mutation was absent inboth sibs of the patient.

Case 2

This male patient (Fig. 1, IV-2), age 11 years, wasreferred because of a family history of Fabry disease.His medical history disclosed celiac disease, diagnosedby a jejunal biopsy, for which he was treated with a

gluten restricted diet since age 16 months. From age 8years on he complained of progressive painful sensa-tions in palms and soles provoked by excercise. Theseepisodes lasted for about half an hour and disappearedafter having rested. Periods of hypohydrosis and com-plaints of constant discomfort were also present.

At age 11 years his height was 141cm (10th centile)and weight 32.9 kg (50th centile). He presented highscapulae, stiff walking gait, and accentuated deep ten-don reflexes bilaterally. There were no skin abnormali-ties, but he had minor mitral valve insufficiency. Ra-diographs showed generalized low bone density with-out any other specific abnormalities. On slit-lampexamination, a cloudy cornea and lenticular opacities,characteristic of Fabry disease, were noted. a-Gal Aactivity was almost completely absent, confirming thediagnosis Fabry disease (Table I).

Enzyme studies and ophthalmological investigationsidentified carriership for Fabry disease in his mother(Fig. 1, III-6) and sister (Fig. 1, IV-1) (Table I). Hisyounger brother (Fig. 1, IV-3) had a normal a-Gal Aactivity. DNA analyses detected the W226X mutationin the patient, his mother, and sister.

His sister complained of disturbed temperature sen-sation especially triggered by rapid changes in tem-perature and humidity. Acroparesthesia in the patienthas been aggravated in the last 3 years of follow-up.Until now, his growth has been normal and parallelsthe 10th centile as expected by parental heights.

By history, II-3 and I-2 had complaints of hypersen-sitivity to cold temperature and acroparesthesia duringfever. Unfortunately, no medical details are availableabout the other relatives in the family as specific coun-seling and additional investigations were refused.

METHODS

a-Galactosidase A activity was determined essen-tially as described by Mayes et al. [1981] using thefluorogenic substrate 4-methylumbelliferyl-a-galactoside and N-acetylgalactosamine to inhibit aspe-cific a-galactosidases.

DNA analysis has been performed as described[Ploos van Amstel et al., 1994]. The W226X mutationwas confirmed by analysis with the restriction enzymeMaeI. MaeI has been used to identify the mutation inrelatives.

DISCUSSION

Since the first description of this disease in 1898 bythe dermatologists Anderson and Fabry, additional re-ports of Fabry disease have contributed to the delinea-tion of the clinical phenotype [Desnick et al., 1995].Intrafamilial variability was reported in several af-fected kindreds. In 1962, Wise et al. described the clini-cal symptoms of Fabry disease in eight British families,with 21 affected individuals (18 men, 3 women). Theclinical phenotype among male relatives was generallycomparable with differences concerning the presence ofjoint pain and cerebral vascular disease. Pierides et al.[1976] described a family with four affected brotherswho also had familial spastic paraplegia. The age of

Fig. 1. Pedigree of a family with Fabry disease caused by a W226Xmutation. j Male hemizygous for the W226X mutation. ◎ heterozygousfemale.

TABLE I. Biochemical and Clinical Findings in Hetero- andHemizygotes in a Fabry Family*

Subject

Hemizygotes Heterozygotes

III-2 IV-2 II-1 II-3 III-6 IV-1

Agea 18 12 44 ? 38 15a-Gal Ab

(nmol/h/mg) 1.2 0.5 7 ni 15 12

ManifestationsAcroparesthesia + ++ (+) (+) − (+)Angiokeratoma − − − − − −Corneal dystrophy + + ni ? + +Hypohydrosis + + − ? − −Cardiac

manifestation VSD MI − ? − −Other GR, SD Celiac disease − − − −

*a, age at diagnosis in years; b, normal range: 18–50 nmol/h/mg; VSD,ventricular septal defect; MI, mitral valve insufficiency; GR, growth retar-dation; SD, skeletal dysplasia; +, present; ++, severe; −, absent, (+), undercertain circumstances; ni, not investigated; ? unknown.

Fabry Disease 437

onset of painful sensations varied from 5 to 11 years.One of the sibs had an abnormal karyotype (47,XYY).This man was less severely affected than his brothers.In 1978, Spence et al. examined 18 males with Fabrydisease, 17 of whom were members of a single family.They showed that there was a considerable variation inthe clinical expression of the disease, suggesting thepresence of other interacting factors that may influencethe clinical expression. In 1979, Hamers et al. de-scribed the relationship between biochemical and clini-cal symptoms in a large British family. They noted thatthe clinical symptoms in the nine affected males werevariable even among patients of similar age. They con-cluded that this variability must be caused by othergenes and/or environmental factors. In 1990, Beyer etal. reported on two brothers with Fabry disease withdifferences in severity of cardiovascular and renalsymptoms.

A possible interacting factor is the blood group of theaffected male. Hemizygotes and heterozygotes whohave blood group B or AB appear to be more severelyaffected, presumably because of additional accumula-tion of B-specific glycosphingolipids [Wherret and Ha-komori, 1973].

In the present family two affected males presentedwith different clinical symptoms. The propositus had asevere decline in growth, delayed puberty and skeletaldysplasia. These findings, combined with the ‘‘coarse’’face and the joint contractures gave at first a strongsuspicion of a storage disorder, mucopolysaccharidosis,or mucolipidosis. However, the presence of glycolipid-like accumulations in the cornea led to the diagnosisFabry disease. The mild congenital VSD is probably acoincidence in this patient. The other symptoms (acro-megaly-like facial appearance, kyphosis, platyspon-dyly) have been described before in patients with Fabrydisease [Wise et al., 1962].

The propositus’ nephew complained of periods of se-vere unexplained acroparesthesia and a constant feel-ing of discomfort. Apart from a slight generalized de-creased bone density no skeletal abnormalities werepresent. His growth followed the 10th centile. This boywas also treated for celiac disease. Halsted et al. [1975]have first reported on the occurrence of celiac diseasein a patient with Fabry disease. To our knowledge thispatient represents the second example of celiac diseaseoccurring in Fabry disease. Gastrointestinal manifes-tations of Fabry disease are not commonly reported,but may occur more frequently than recognized. Themanifestations include episodic diarrhea, constipation,malabsorption, crampy abdominal pain, nausea, andvomiting. X-ray studies showed motility disturbances,loss of colonic haustral pattern, and persistent colonicspasticity [Rowe et al., 1974]. In a review of the litera-ture Sheth et al. [1981] found seven reports of gastro-intestinal involvement in 12 affected males. Theyevaluated gastrointestinal structure and function in 13affected males and 17 heterozygous females. Gastroin-testinal symptoms were noted in 8 of the 13 males and5 of the 17 females, but malabsorption and celiac dis-ease were excluded. These authors suggested previousunder-diagnosis of gastrointestinal symptoms in Fabrydisease but also concluded that the previously sug-

gested association of celiac disease and Fabry diseasemust have been a coincidence. Given the incidence ofFabry disease of 1:40,000 [Desnick et al., 1995] andthat of celiac sprue ranging from 1:300 to 1:2,000 [My-lotte et al., 1973; Trier, 1991], the expected combinedfrequency of Fabry disease and celiac disease, assum-ing a coincidence, can be estimated a 1:40,000,000. Be-cause this specific combination has now been reportedtwice in approximately 20 years time, we also concludethat there is no association between celiac disease andFabry disease. However, we recommend that everyFabry patient with intestinal symptoms or retardedstatural growth should be screened for intestinal mal-absorption due to celiac disease.

Angiokeratoma may be one of the earliest manifes-tations of Fabry disease and may lead to diagnosis inchildhood. Typically, these lesions can be found in clus-ters around the umbilical area, on the buttocks, thethighs, hips, penis, and scrotum. None of the here re-ported family members had angiokeratoma.

This report emphasizes the importance of document-ing clinical symptoms of a disease within one family. Inthe absence of a positive family history, the diagnosisFabry disease can be easily missed, especially when thetypical skin abnormalities are not present.

ACKNOWLEDGMENTS

The authors thank the participating family, C. J. M.van der Sijs-Bos, S. Malcolm, and B. Winchester fortheir contribution to this manuscript.

REFERENCES

Beyer E, Djatlovitskaya E, Zairatyants O, Berestova A, Mendelson M,Brook E, Wiederschain G. 1990. Identification of Fabry disease in twobrothers. J Inher Metab Dis 13:230–231.

Bishop DF, Kornreich R, Desnick RJ. 1988. Structural organization of thea-galactosidase A gene: further evidence for the absence of a 38 un-translated region. Proc Natl Acad Sci USA 85:3903–3907.

Davies JP, Christomanou H, Winchester B, Malcolm S. 1994. Detection of8 new mutations in the a-galactosidase A gene in Fabry disease. HumMol Genet 3:667–669.

Davies JP, Eng CM, Hill JA, Malcolm S, MacDermot K, Winchester B,Desnick RJ. 1996. Fabry disease: fourteen a-Galactosidase A muta-tions in unrelated families from the United Kingdom and other Euro-pean countries. Eur J Hum Genet 4:219–224.

Desnick RJ, Ioannou YA, Eng C. 1995. a-Galactosidase deficiency: Fabrydisease. In: Scriver CR, Beaudet AL, Sly WS, Valle D, editors. Themetabolic and molecular bases of inherited disease, 7th ed. New York:McGraw-Hill. p 2741–2784.

Eng CM, Desnick RJ. 1994. Molecular basis of Fabry disease: mutationsand polymorphisms in the human a-galactosidase A gene. Hum Mutat3:103–111.

Eng CM, Niehaus DJ, Enriquez AL, Burgert TS, Ludman MD, Desnick RJ.1994. Fabry disease: twenty-three mutations including sense and an-tisense CpG alterations and identification of a deletional hot-spot inthe a-galactosidase A gene. Hum Mol Genet 3:1795–1799.

Halsted CH, Rowe JW. 1975. Occurrence of celiac sprue in a patient withFabry’s disease. Ann Intern Med 83:524–525.

Hamers MN, Wise D, Ejiofor A, Strijland A, Robinson D, Tager JM. 1979.Relationship between biochemical and clinical features in an EnglishAnderson-Fabry family. Acta Med Scand 206:5–10.

Mayes JS, Scheerer JB, Sifers RN, Donaldson ML. 1981. Differential assayfor lysosomal a-galactosidases in human tissue and its application toFabry’s disease. Clin Chim Acta 112:247–251.

Mylotte M, Egan-Mitchell B, McCarthy CF, McNicholl B. 1973. Incidenceof coeliac disease in the west of Ireland. Br Med J 1:703–705.

438 Knol et al.

Pierides AM, Holti G, Crombie AL, Roberts DF, Gardiner SE, Colling A,Anderson J. 1976. Study on a family with Anderson-Fabry’s diseaseand associated familial spastic paraplegia. J Med Genet 13:455–461.

Ploos van Amstel JK, Jansen RPM, de Jong JGN, Hamel BCJ, Wevers RA.1994. Six novel mutations in the a-galactosidase A gene in familieswith Fabry disease. Hum Mol Genet 3:503–505.

Rowe JW, Gilliam JI, Warthin TA. 1974. Intestinal manifestations of Fab-ry’s disease. Ann Intern Med 81:628–631.

Sheth KJ, Werlin SL, Freeman ME, Hodach AE. 1981. Gastrointestinalstructure and function in Fabry’s disease. Am J Gastro 76:246–251.

Spence MW, Clarke JTR, D’Entremont DM, Sapp GA, Smith ER, Gold-bloom AL, Davar G. 1978. Angiokeratoma corporis diffusum (Ander-son-Fabry disease) in a single large family in Nova Scotia. J Med Genet15:428–434.

Trier JS. 1991. Celiac sprue. N Engl J Med 325:1709–1719.

Wherret JR, Hakomori S. 1973. Characterization of a bloodgroup B glyco-lipid, accumulating in the pancreas of a patient with Fabry’s disease. JBiol Chem 218:3046–3051.

Wise D, Wallace HJ, Jellinek EH. 1962. Angiokeratoma corporis diffusum,a clinical study of eight affected families. Q J Med 31:177–206.

Fabry Disease 439