American Journal of Medical Genetics 37:289 (1990)
Letter to the Editor Duchenne-Like Muscular Dystrophy in the Arabs To the Editor: The prevalence of autosomal recessive (AR) “DUchenne-like” dystrophy in the highly inbred population of Kuwait, a s estimated by Farag and Teebi [19901, is apparently much higher than in other countries in which there is a lower rate of consanguinity. The authors found that in eight among 22 pedigrees there is a t least one affected girl with normal chromosome constitution, confirming therefore AR inheritance. However, they did not specify-among the 14 genealogies with only affected males-how many represent familial or isolated cases. Such Classification is extremely important because of the known ascertainment bias toward familial cases, and, in the case of DMD, most cases are isolated (294 among 450 in our reported study).Therefore, the 14 families with DMD patients with possible X-linked inheritance studied by the authors might not be representative of the population of Kuwait, which might lead to a n overestimate of the frequency of AR-“DMD-like” cases. In any case, the classification of patients with a Duchenne phenotype and AR inheritance, can now be confirmed through dystrophin assessment [Francke et al., 1989; Hoffman et al., 1988; Vainzof et al., 19901. The identification of such cases is extremely important for
Received for publication February 13, 1990.
0 1990 Wiley-Liss, Inc.
genetic counseling, in particular for the proband’s sisters and for planning future pregnancies for the patient’s parents.
REFERENCES Farag I, Teebi AS (1990): Letter to the Editor: Duchenne-like muscular dystrophy in the Arabs. Am J Med Genet 37:OOO-000. Francke U, Darras BT, Hersh J H , Berg BO, Miller RG (1989):Brother/ sister pairs affected with early-onset, progressive muscular dystrophy: Molecular studies reveal etiologic heterogeneity. Am J Hum Genet 45:63-72. Hoffman EP, Fischbeck KH, Brown RH, Johnson M, Medori R, Loike JD, Harris JB, Waterston R, Brooke M, Specht L, Kupsky W, Chamberlain J , Caskey T, Shapiro F, Kunkel LM (1988): Characterization of dystrophin in muscle-biopsy specimens from patients with Duchenne’s or Becker’s muscular dystrophy. N Engl J Med 318: 1363-1368. Vainzof M, Pavanello RCM, Pavanello-Filho I, Rapaport D, PassosBueno MR, Zubrzycka-Gaarn E, Bulman DE, Zatz M: Screening of male patients with autosomal recessive Duchenne dystrophy through dystrophin and DNA studies (submitted for publication).
Mayana Zatz Maria Rita Passos-Bueno Debora Rapaport Departamento de Biologia Instituto de Biociencias Universidade de Sao Paulo S ~ Paulo, O Brazil
Letter to the Editor Duchenne-Like Muscular Dystrophy in the Arabs To the Editor: The prevalence of autosomal recessive (AR) “DUchenne-like” dystrophy in the highly inbred population of Kuwait, a s estimated by Farag and Teebi [19901, is apparently much higher than in other countries in which there is a lower rate of consanguinity. The authors found that in eight among 22 pedigrees there is a t least one affected girl with normal chromosome constitution, confirming therefore AR inheritance. However, they did not specify-among the 14 genealogies with only affected males-how many represent familial or isolated cases. Such Classification is extremely important because of the known ascertainment bias toward familial cases, and, in the case of DMD, most cases are isolated (294 among 450 in our reported study).Therefore, the 14 families with DMD patients with possible X-linked inheritance studied by the authors might not be representative of the population of Kuwait, which might lead to a n overestimate of the frequency of AR-“DMD-like” cases. In any case, the classification of patients with a Duchenne phenotype and AR inheritance, can now be confirmed through dystrophin assessment [Francke et al., 1989; Hoffman et al., 1988; Vainzof et al., 19901. The identification of such cases is extremely important for
Received for publication February 13, 1990.
0 1990 Wiley-Liss, Inc.
genetic counseling, in particular for the proband’s sisters and for planning future pregnancies for the patient’s parents.
REFERENCES Farag I, Teebi AS (1990): Letter to the Editor: Duchenne-like muscular dystrophy in the Arabs. Am J Med Genet 37:OOO-000. Francke U, Darras BT, Hersh J H , Berg BO, Miller RG (1989):Brother/ sister pairs affected with early-onset, progressive muscular dystrophy: Molecular studies reveal etiologic heterogeneity. Am J Hum Genet 45:63-72. Hoffman EP, Fischbeck KH, Brown RH, Johnson M, Medori R, Loike JD, Harris JB, Waterston R, Brooke M, Specht L, Kupsky W, Chamberlain J , Caskey T, Shapiro F, Kunkel LM (1988): Characterization of dystrophin in muscle-biopsy specimens from patients with Duchenne’s or Becker’s muscular dystrophy. N Engl J Med 318: 1363-1368. Vainzof M, Pavanello RCM, Pavanello-Filho I, Rapaport D, PassosBueno MR, Zubrzycka-Gaarn E, Bulman DE, Zatz M: Screening of male patients with autosomal recessive Duchenne dystrophy through dystrophin and DNA studies (submitted for publication).
Mayana Zatz Maria Rita Passos-Bueno Debora Rapaport Departamento de Biologia Instituto de Biociencias Universidade de Sao Paulo S ~ Paulo, O Brazil
