Gulden Diniz1, Hulya Tosun Yildirim2, Gulcin Akinci3, Filiz Hazan4, Aysel Ozturk3, Kanay Yararbas5, Ajlan Tukun6. 1. Basic Oncology, Associate Professor in Pathology, Tepecik Research Hospital, Izmir, Turkey. Electronic address: agdiniz@gmail.com. 2. Pathology Department, Dr. Behcet Uz Children's, Research Hospital, Izmir, Turkey. 3. Pediatric Neurology Department, Dr. Behcet Uz Children's, Research Hospital, Izmir, Turkey. 4. Medical Genetics Department, Dr. Behcet Uz Children's, Research Hospital, Izmir, Turkey. 5. Medical Genetics Department, Duzen Laboratories, Istanbul and Ankara, Turkey. 6. Medical Genetics Department, Duzen Laboratories, Istanbul and Ankara, Turkey; Medical Genetics Department, Ankara University Medical School, Ankara, Turkey.
Abstract
BACKGROUND: The sarcoglycan alpha gene, also known as the adhalin gene, is located on chromosome 17q21; mutations in this gene are associated with limb-girdle muscular dystrophy type 2D. We describe two Turkish siblings with findings consistent with limb-girdle muscular dystrophy type 2D. The evaluation excluded a dystrophinopathy, which is the most common form of muscular dystrophy. PATIENTS: Both siblings had very high levels of creatinine phosphokinase and negative molecular tests for deletions and duplications of the dystrophin gene. The older boy presented at 8 years of age with an inability to climb steps and an abnormal gait. His younger brother was 5 years old and had similar symptoms. The muscle biopsy evaluation was performed only in the older brother. RESULTS: The muscle biopsy showed dystrophic features as well as a deficiency in the expression of two different glycoproteins: the alpha sarcoglycan and the gamma sarcoglycan. Sarcolemmal expressions of dystrophin and other sarcoglycans (beta and delta) were diffusely present. DNA analysis demonstrated the presence of previously unknown homozygous mutations [c.226 C > T (p.L76 F)] in exon 3 in the sarcoglycan alpha genes of both siblings. Similar heterozygous point mutations at the same locus were found in both parents, but the genes of beta, delta, and gamma sarcoglycan were normal in the remaining family members. CONCLUSIONS: We describe two siblings with limb-girdle muscular dystrophy type 2D with a novel missense mutation. These patients illustrate that the differential diagnosis of muscular dystrophies is impossible with clinical findings alone. Therefore, a muscle biopsy and DNA analysis remain essential methods for diagnosis of muscle diseases.
BACKGROUND: The sarcoglycan alpha gene, also known as the adhalin gene, is located on chromosome 17q21; mutations in this gene are associated with limb-girdle muscular dystrophy type 2D. We describe two Turkish siblings with findings consistent with limb-girdle muscular dystrophy type 2D. The evaluation excluded a dystrophinopathy, which is the most common form of muscular dystrophy. PATIENTS: Both siblings had very high levels of creatinine phosphokinase and negative molecular tests for deletions and duplications of the dystrophin gene. The older boy presented at 8 years of age with an inability to climb steps and an abnormal gait. His younger brother was 5 years old and had similar symptoms. The muscle biopsy evaluation was performed only in the older brother. RESULTS: The muscle biopsy showed dystrophic features as well as a deficiency in the expression of two different glycoproteins: the alpha sarcoglycan and the gamma sarcoglycan. Sarcolemmal expressions of dystrophin and other sarcoglycans (beta and delta) were diffusely present. DNA analysis demonstrated the presence of previously unknown homozygous mutations [c.226 C > T (p.L76 F)] in exon 3 in the sarcoglycan alpha genes of both siblings. Similar heterozygous point mutations at the same locus were found in both parents, but the genes of beta, delta, and gamma sarcoglycan were normal in the remaining family members. CONCLUSIONS: We describe two siblings with limb-girdle muscular dystrophy type 2D with a novel missense mutation. These patients illustrate that the differential diagnosis of muscular dystrophies is impossible with clinical findings alone. Therefore, a muscle biopsy and DNA analysis remain essential methods for diagnosis of muscle diseases.
Authors: Hemakumar M Reddy; Sherifa A Hamed; Monkol Lek; Satomi Mitsuhashi; Elicia Estrella; Michael D Jones; Lane J Mahoney; Anna R Duncan; Kyung-Ah Cho; Daniel G Macarthur; Louis M Kunkel; Peter B Kang Journal: Muscle Nerve Date: 2016-08-24 Impact factor: 3.217
Authors: Madhurima Saha; Hemakumar M Reddy; Mustafa A Salih; Elicia Estrella; Michael D Jones; Satomi Mitsuhashi; Kyung-Ah Cho; Silveli Suzuki-Hatano; Skylar A Rizzo; Muddathir H Hamad; Maowia M Mukhtar; Ahlam A Hamed; Maha A Elseed; Monkol Lek; Elise Valkanas; Daniel G MacArthur; Louis M Kunkel; Christina A Pacak; Isabelle Draper; Peter B Kang Journal: Physiol Genomics Date: 2018-08-31 Impact factor: 3.107