Phenotype–genotype correlation in 91 patients with familial Mediterranean fever reveals a high frequency of cutaneomucous features

Paediatric Rheumatology/Section Editor: P. Woo

I. Koné Paut, M. Dubuc1, J. Sportouch, P. Minodier, J. M. Garnier and I. Touitou2

Service de Pédiatrie, Hôpital Nord, chemin des Bourrelys, 13915 Marseille cedex 20,
1 Service d'information médicale, Hôpital Nord, chemin des Bourrelys, 13915 Marseille cedex 20 and
2 Laboratoire de Génétique moléculaire et chromosomique, Hôpital Arnaud de Villeneuve, 379 avenue du doyen Giraud, 34 295 Montpellier cedex, France


    Abstract
 Top
 Abstract
 Introduction
 Patients and methods
 Results
 Discussion
 References
 
Objectives. To describe the clinical manifestations of familial Mediterranean fever (FMF) in 91 patients from 47 families and provide data from the genetic study.

Patients and methods. We conducted a retrospective chart review of 91 patients (including 83 children aged <15 yr) from 47 families through a questionnaire and a specific database. The genetic analysis included complete screening of known mutations of the MEFV gene on chromosome 16p13.3. A positive diagnosis required at least two mutations, one on each chromosome.

Results. Our panel included 52 females and 39 males, with a mean age of 7.27 yr. Of the 47 families, 31 were non-Ashkenazi Jews, 10 were Armenians and six were from other ethnic groups. Clinical features included fever (100%), peritonitis (86%), pleuritis (56%), arthritis (34%) and myalgias (27%). We observed a high rate of cutaneous manifestations (47%); erythema, oedema and recurrent oral ulcers were the most frequent. Phenotype–genotype correlations showed a significant association of M694V homozygosity with earlier age of onset (P = 0.044), fever >39°C (P = 0.002), pleural crisis (P = 0.0044), splenomegaly (P = 0.0005) and arthritis (P = 0.001). Associations with mucocutaneous features were as follows: erysipelas-like erythema (P = 0.012), oedema (P = 0.61, not significant) and oral ulcers (P = 0.45, not significant).

Conclusion. New phenotype–genotype correlations emerged from our study: homozygosity for the M694V mutation was associated with intensity of fever, splenomegaly and with erysipelas-like erythema. Apart from erysipelas-like erythema, no significant association was found between other cutaneous features and the genotype.

KEY WORDS: Familial Mediterranean fever, Childhood, Mucocutaneous manifestations, Phenotype–genotype correlation.


    Introduction
 Top
 Abstract
 Introduction
 Patients and methods
 Results
 Discussion
 References
 
Familial Mediterranean fever (FMF) is a recessive disorder that predominantly affects a few ethnic groups, including non-Ashkenazi Jews, Armenians, Turks and Arabs. First manifestations usually appear by 4 yr of age and are characterized by recurrent bouts of fever and polyseritis, skin rashes and myositis. These features are not specific, and the disease is often diagnosed retrospectively on the basis of unexplained recurrent febrile attacks and a positive familial history [1].

The gene responsible for FMF, MEFV, has been identified on chromosome 16p13.3 by French and international consortia [2, 3]. MEFV includes 10 exons. Most DNA changes are nucleotide substitutions, which occur in the last exon in more that 80% of typical cases. Other, less common mutations have been found in exons 2, 3 and 5 [48]. The function of the corresponding protein, marenostrin/pyrin, is unknown. The genetic method is at present the only specific way of diagnosing FMF. Teams are identifying novel mutations and establishing phenotype–genotype correlations to increase the specificity and sensitivity of the tests.

The purpose of our study was to provide clinical information and genetic data on about 91 FMF patients (including 83 children aged < 5 yr) from 47 families, emphasizing cutaneous features.


    Patients and methods
 Top
 Abstract
 Introduction
 Patients and methods
 Results
 Discussion
 References
 
Families were recruited through 47 paediatric probands who satisfied the criteria for FMF and attended the department of paediatrics, North Hospital, Marseilles, France [9]. Information was collected from medical charts and by an interview if necessary, with particular attention to mucocutaneous symptoms. A specific questionnaire and database were created. After agreement by the CCPPRB ethics committee of Montpellier, informed consent was obtained from all patients and other family members before they entered the study.

DNA analysis was performed in the Laboratory of Genetics at Montpellier, France. Density gradient gel electrophoresis was used for general screening of exon 10. If a new pattern was detected, the polymerase chain reaction fragments were sequenced. A complementary method was used systematically for the following mutations: ARMS for codon 694 mutation analysis [M694V and M694I] and restriction fragment length polymorphism (RFLP) for V726A, M680I and R761H. RFLP was performed on exon 2 to identify the E148Q, T267I and E167D DNA changes. A positive test required at least two mutations, one on each chromosome (homozygosity or compound heterozygosity) [8]. Eighty-eight parents’ chromosomes were tested to phase the patients’ mutations, so as to ascertain that each mutation was on a different chromosome and to collect matched control chromosomes.

Statistical analysis
Differences between DNA changes in each group of patients were assessed using the {chi}2 test and Fisher's exact test. A P value < 0.05 was considered significant.


    Results
 Top
 Abstract
 Introduction
 Patients and methods
 Results
 Discussion
 References
 
Epidemiology
Our patients were 39 males and 52 females (sex ratio 0.75). Among the 47 families, 31 (76%) were non-Ashkenazi Jews, 10 (16%) were Armenians, three were Arabs, two were of southern European ancestry and one was Turkish. Consanguinity was present in four families including six patients. The age at onset was under 15 yr in 83 (91%) of them; mean age was 7.3 yr (S.D. 9.4), with no significant difference between the sexes (P = 0.5). The delay in diagnosis was <2 months for 25 patients, between 2 months and 5 yr for 49, and >5 yr for the remaining 17. FMF was recognized at a mean age of 13.4 yr (S.D. 13.6), with particularly late diagnosis in three patients (19–51 yr). The mean age at the time of the study was 27.6 yr (S.D. 18.3). The attacks recurred at least once a month in 75% of cases, and between two and four times a year in the other 25%. Symptoms lasted 24 h in 15%, 48 h in 35%, 72 h in 25% of patients, and >3 days in the other 25%.

Clinical features
Initial symptoms could be retrieved in 64 patients; these included isolated fever (25%) or peritonitis (19%), fever plus peritonitis (32%), pleuritis (6.3%), arthritis (17%) and aseptic meningitis in a 10-month-old boy who presented with sustained febrile seizures. Clinical symptoms were reported for 88 patients (Table 1Go). In this table, we report only features that had been clearly established; for several symptoms there are fewer than 88 patients. Fever was present in all cases, and was >39°C in 76%. Peritonitis was manifested as abdominal crisis (85%), vomiting (26%) and diarrhoea (20%). In addition, 31% of patients had had an appendectomy. Persistent splenomegaly was confirmed in 34% of cases, and hepatomegaly in only two patients. Thoracic pain was present in 55% of cases. Among the 88 patients, 46% had arthralgias (including 73% with arthritis). The course was essentially oligoarticular and involved the ankles (92%) and knees (57%). The wrists, hips and small joints were less often affected. Spondylitis was observed in a 3-yr-old patient with a family history of bipolar aphthosis and Behçet's disease. Transient myalgias accounted for 27% of cases. Renal symptoms were persistent proteinuria in six adult patients in whom definite amyloidosis was not confirmed by histology. Four other patients had transient haematuria with acute glomerulonephritis in one case.


View this table:
[in this window]
[in a new window]
 
TABLE 1. Clinical features in 88 symptomatic patients with FMF

 

Mucocutaneous features
Cutaneomucous signs were reported in 42/88 symptomatic patients (47%). Erythema including erysipeloid plaques was the most frequent feature (19 patients; 45%) (Table 2Go). The inferior limbs were primarily involved over the ankles and the dorsal region of the feet (14/19; 74%). Multiple erythemas occurred in 32% of cases. Localized oedemas were reported in 16/42 patients (38%). The areas involved were as follows: inferior limbs (11/16), upper limbs (9/16), face (3/16) and neck (1/16). Multiple locations were observed in 7/16 patients (43%). None of these patients had renal failure or C1-inhibitor deficiency. Other associated rashes included vasculitic purpura of the inferior limbs (3/42), psoriasis (3/42), herpes (2/42), urticaria (2/42) and erythema nodosum (2/42). Recurrent oral ulceration occurred in 9/42 patients (21%).


View this table:
[in this window]
[in a new window]
 
TABLE 2. Mucocutaneous signs in 42 patients with FMF

 

Associated diseases
Ulcerative colitis, Crohn's disease and thyroiditis were associated in three patients. Five other patients had a family history of pelvispondylitis. Bipolar aphthosis was present in three members of a patient family, two of these members had Behçet's disease.

Treatment
All the 88 symptomatic patients received between 0.5 and 2 mg/day of colchicine. Complete remission was obtained in only 12% of cases; most patients (55%) showed a partial effect, i.e. lower grade symptoms and less frequent attacks under treatment. For 33% of patients colchicine was poorly or not effective.

Genetic diagnosis and clinical correlation
Genetic diagnosis was performed in all 91 cases. Mutations of the MEFV gene were found in 82 (90%) of them: there were 48 homozygotes, 13 compound heterozygotes and 21 patients with only one mutation. Mutations of codon 694 were the most frequent (90%; 74/82); they were found in 100% of non-Ashkenazi Jewish patients. Homozygosity for the M694V mutation was found in 73% of the non-Ashkenazi Jews (P < 0.00005). Compound heterozygotes were distributed as follows: M694V/V726A (9), M680I/M694V (2), M680I/V726A (1), M694V/E148Q (1) and M694V/M694I (2). Numbers of heterozygotes for the mutations were 13 for M694V, three for V726A, three for M680I (3) and two for M694I. In addition, two patients had rare mutations: A744S in exon 10 and L110P in exon 2.

Homozygosity for the M694V mutation correlated with earlier age of onset (mean 4.5 vs 10.2 yr; P = 0.044), fever >39°C (P = 0.002), pleural crisis (P = 0.0044), splenomegaly (P = 0.0005) and arthritis (P = 0.001) (Fig. 1GoGo). No correlation was found with the frequency of attacks, myalgias, arthralgias or proteinuria. Correlations between M694V homozygosity and mucocutaneous features were as follows: erysipeloid erythema (P = 0.012), oedema (P = 0.6) (not significant), oral ulcers (P = 0.45, not significant). Analysis of control chromosomes showed that three asymptomatic relatives had two mutations: M694V/M694V, M694V/V726A and M694V/M680I. No mutation was found in the other control chromosomes.



View larger version (33K):
[in this window]
[in a new window]
 
FIG. 1. Association of M694V homozygosity with clinical features.

 


    Discussion
 Top
 Abstract
 Introduction
 Patients and methods
 Results
 Discussion
 References
 
Our data show that FMF is not an uncommon condition in children attending a paediatric rheumatology department in the south of France. The epidemiological findings in terms of male to female ratio (0.7), age of onset, age of diagnosis, and time for delay in diagnosis were similar to those in previously reported paediatric series [1015]. A typical clinical pattern was observed in most of our patients, most of whom were non-Ashkenazi Jews. Clinical features included attacks of fever (100%), peritonitis (85%), pleuritis (55%) and arthritis (34%). The frequency of mucocutaneous features was 47%, much higher than expected. Indeed, this particular aspect of FMF has always been neglected in the large series of adult patients with FMF [1, 4]. Erysipelas-like erythema involving the joints and the dorsa of the feet is considered characteristic of the disease, but the frequency varies among adult series, probably because of differences among populations but also because of variable interest on the part of physicians [4, 7]. This specific feature was the most common in our mostly paediatric series of patients (19 of 91 (20%), including 49% with skin manifestations). It was in most cases concomitant with ankle arthritis. Our findings agree with those of Majeed et al. [15], who gave a thorough description of 43 Arab children, of whom 43% had cutaneous features (18% with erysipelas-like erythema). However, in a recent review by the same authors including 470 children, the frequency of cutaneous signs fell to 12% [16]. Cutaneous signs are currently neglected in most reported series of FMF patients; the frequency of those reported was notably lower than ours [16]. We also observed multiple erythema over the face, trunk and limbs of several patients. Self-limited swelling mimicking angioneurotic oedema, especially over the hands and face, was also frequent (16/91; 17%) (10% in the series of Majeed et al. [16]). Much attention has been paid to the association of FMF with Henoch–Schönlein purpura (HSP), which has a frequency of 10% in some paediatric series [17]. Moreover, it has been demonstrated that IgA nephropathy is associated with syndromes including mucosal injury and a demonstrable immune response leading to the formation, circulation and deposition of IgA in other partially hereditary disorders, such as seronegative spondyloarthropathies and Behçet's disease (BD) [18, 19]. Three of our patients had non-specific purpuric rash of the lower limbs without definite HSP or IgA nephropathy. This purpuric rash was mentioned in a large series of patients from different ethnic groups [1]. For some authors this manifestation is the most common in FMF, reaching 26–63%. The presence of erythema nodosum and psoriasis in a few patients is of interest because these symptoms may be genetically related to FMF. Furthermore, recurrent oral ulceration was relatively frequent in our series (10%), with familial history of bipolar ulcers and BD in one case. Because our patients were carefully interviewed and examined for mucosal symptoms, it is difficult to assess the significance of oral ulcers in FMF in comparison with the general population. The presence of genital ulceration is of interest because this trait is more often associated with another trait resembling inflammatory disorder (BD). Moreover, there are few reports of familial association of FMF and BD [19]. Recurrent oral ulceration may be a common characteristic of both diseases; however, a true genetic link could also exist and could be accurately evaluated by further genetic studies. Phenotype–genotype correlation in our patients showed very significant association between the M694V mutation and non-Askenazi Jewishness (P < 0.000001). Homozygosity for M694V was significantly associated with a more severe course, as demonstrated in previous series [7, 14, 20]. Our results were concordant in terms of earlier age of onset and more frequent arthritis and pleuritis. Furthermore, new phenotype–genotype correlations emerged from our study. Although cutaneous signs have been reported previously, no significant association with M694V homozygosity was detected [6, 7, 14]. A preliminary report by Pras et al. [21] showed an association of M694V homozygosity with erysipelas-like erythema. Here, we studied each cutaneous feature separately and found that M694V homozygosity correlated with erysipela-like erythema only. Two other signs have never been tested: splenomegaly and intensity of fever. Both also correlated with M694V homozygosity. The presence of two MEFV gene mutations in three symptom-free individuals could be explained by incomplete penetrance and by the additional effect of a milder mutation, as suspected for the V726A mutation. The absence of identifiable DNA changes in nine patients suggests that other MEFV gene mutations remain to be determined. However, some of these patients may suffer from a yet unknown periodic inflammatory disorder resembling FMF.

In summary, we confirm that M694V homozygosity is associated with a more severe course in FMF patients. Mucocutaneous manifestations were found to be frequent. Further studies with prospective evaluation are needed to complete the dermatological study of FMF and to establish its correlation with MEFV gene mutations.


    Notes
 
Correspondence to: I. Koné Paut. Back


    References
 Top
 Abstract
 Introduction
 Patients and methods
 Results
 Discussion
 References
 

  1. Sohar E, Gafni J, Pras M, Heller H. Familial Mediterranean fever. A survey of 470 cases and review of the literature. Am J Med1986;43:227–52.
  2. The French FMF consortium. A candidate gene for familial Mediterranean fever. Nature Genet1997;17:25–31.[ISI][Medline]
  3. The International FMF consortium. Ancient missense mutations in a new member of the RoRet gene family are likely to cause familial Mediterranean fever. Cell1997;90:797–807.[ISI][Medline]
  4. Samuels J, Aksentijevich I, Torosyan Y, Centola M, Deng Z, Sood R et al. Familial Mediterranean fever at the millennium. Medicine1998;77:268–97.[ISI][Medline]
  5. Aksentijevich I, Torosyan Y, Samuels J, Centola M, Pras E, Chae JJ et al. Mutation and haplotype studies of familial Mediterranean fever reveal new ancestral relationships and evidence for a high carrier frequency with reduced penetrance in the Ashkenazi Jewish population. Am J Hum Genet1999;64:949–62.[ISI][Medline]
  6. Cazeneuve C, Sarkisian T, Pêcheux C, Dervichian M, Nedelec B, Reinert P et al. MEFV gene analysis in Armenian patients with familial Mediterranean fever: diagnostic value, unfavorable renal prognosis of the M694V homozygous genotype, genetic and therapeutic implications. Am J Hum Genet1999;65:88–97.[ISI][Medline]
  7. Dewalle M, Domingo C, Rozenbaum M, Ben-Chetrit E, Cattan D, Bernot A et al. Phenotype–genotype correlation in Jewish patients suffering from familial Mediterranean fever. Eur J Hum Genet1998;6:95–7.[ISI][Medline]
  8. Touitou I, Ben-Chetrit EL, Nortarnicola C et al. Familial Mediterranean fever. Clinical and genetic features in Druzes and in Iraqi Jews: A preliminary study. J Rheumatol1998;25:916–9.[ISI][Medline]
  9. Livneh A, Langevitz P, Zemer D, Zaks N, Kees S, Lidar T et al. Criteria for the diagnosis of familial Mediterranean fever. Arthritis Rheum1997;40:1879–85.[ISI][Medline]
  10. Saatcçi Ü, Ozen S, Özdemir A, Bakkaloglu A, Besbas N, Topaloglu R et al. Familial Mediterranean fever in children: report of a large series and discussion of the risk and prognostic factors of amyloidosis. Eur J Pediatr1997;156:619–23.[ISI][Medline]
  11. Rawashdeh MO, Majeed HA. Familial Mediterranean fever in Arab children: the high prevalence and gene frequency. Eur J Pediatr1996;155:540–4.[ISI][Medline]
  12. Shapiro TR, Ehrenfeld EN. Familial Mediterranean fever: recurrent hereditary polyserositis in children. Pediatrics1962;30:443–9.[Abstract]
  13. Majeed HA, Barakat M. Familial Mediterranean fever in children: analysis of 88 cases. Eur J Pediatr1989; 148:637–41.
  14. Brik R, Shinawi M, Kepten I, Berant M, Gershoni-Baruch R. Familial Mediterranean fever. Clinical and genetic characterization in a mixed pediatric population of Jewish and Arab patients. Pediatrics1999;103:e70.[Abstract/Free Full Text]
  15. Majeed HA, Quabazard Z, Hijazi Z, Farwana S, Harshani F. The cutaneous manifestations in children with familial Mediterranean fever (recurrent hereditary polyserositis). A six year study. Q J Med1990;75:607–16.[ISI][Medline]
  16. Majeed HA, Rawashdeh M, El Shanti H, Qubain H, Khuri-Bulos, Shahin M. Familial Mediterranean fever in children: the expanded profile. Q J Med1999;92:309–18.[ISI]
  17. Flatau E, Khon D, Schiller D, Lurie M, Levy E. Schönlein–Henoch syndrome in patients with familial Mediterranean fever. Arthritis Rheum1982;25:42–7.[ISI][Medline]
  18. Said R, Nasrallah N, Hamza Y, Tarawneh M, Al-Khattib M. IgA nephropathy in patients with familial Mediterranean fever. Am J Nephrol1988;8:417–20.[ISI][Medline]
  19. Schwartz T, Langevitz P, Zemer D, Pras M, Livneh A. Increased incidence of Behçet's disease in familial Mediterranean fever. In: Sohar E, Gafni J, Pras M, eds. Familial Mediterranean fever. Tel Aviv: Freund Publishing, 1997:148–50.
  20. Shohat M, Magal N, Shohat T, Chen X, Dagan T, Mimouni A et al. Phenotype–genotype correlation in familial Mediterranean fever: evidence for an association between Met694Val and amyloïdosis. Eur J Hum Genet1999;7:287–92.[ISI][Medline]
  21. Pras E, Langevitz P, Livneh A, Zemer D, Migdal A, Padeh S et al. Genotype–phenotype correlation in familial Mediterranean fever, a preliminary report. In: Sohar E, Gafni J, Pras M, eds. Familial Mediterranean fever. Tel Aviv: Freund Publishing, 1997:260–4.
Submitted 9 December 1999; revised version accepted 12 June 2000.