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[b] a significant number of cases occurring below 50years of age, [c] Absence of gastric cancer as part ofcancer family syndrome, [d] additional risk posed byfried food. Since patient number was small, these resultsneed confirmation by larger field studies.

G Ray+, S Dey*, S Pal++Senior Medical Officers; *Post Graduate [DNB] Trainee,Gastroenterology Unit, Department of Medicine, B.R. Singh(Central) Hospital, Eastern Railway, Sealdah, Kolkata.Received : 28.5.2005; Revised : 12.12.2006; Accepted :30.1.2007

REFERENCES1. Cancer. In: K Park, Ed. Parks Textbook of Preventive and

Social Medicine (18th edition). Jabalpur: M/S Banarsidas BhanotPublisher. 30210.

2. Development of An Atlas of Cancer in India. First All IndiaReport 20012002. Nandakumar A, Gupta PC, Eds. NationalCancer Registry Programme (ICMR), Bangalore, 2004.

3. Malhotra SL. Geographic distribution of gastrointestinal cancerin India with special reference to causation. Gut 1967;8:36172.

Myotonic Muscular Dystrophy

Sir,

The disease is seen worldwide with a particularlyhigh frequency in French Canadians in Quebec where allcases can be traced to a single ancestor.1-3 The molecular basis of disease lies in expansion of a trinucleotide(cytosine thymine guanine CTG) repeat sequencein the 3untranslated region of the myotonic dystrophyprotein kinase (DMPK) gene on chromosome 19q. Thisexpanded gene is unstable and its size increases withage. The size of repeat on gene is directly proportional

to clinical severity of disease and has inverse relationwith age of onset of the disease.1-3

25-years-old male presented with decreased powerof gripping, which progressed to difficulty in holdingobjects in hands over 5 years. There was difficulty inholding neck while getting up from lying down positionand dysphagia, and nasal intonation of voice alongwith nasal regurgitation of fluids for last 3 years. Therewas no family history of the disease. On examinationatrophy of muscles of face (hatchet shaped face),temporalis, masseter along with sternocleidomastoid bilaterally was noted (Fig. 1). Percussion myotonia

could be demonstrated both on thenar muscles (Fig.2) and tongue. Rest of neurological examination andsystemic examination was normal. EMG studies showedmyotonia along with decreased amplitude of actionpotentials and polyphasic potentials. Muscle biopsyrevealed muscle fibers of variable size with atrophy offibers. There was presence of central nuclei and ringfibers.

`Classical form' of the disease is seen in adolescentor early adult life with variable presenting features.Muscular weakness, myotonia, mental retardation,cataract, neonatal problems are common symptoms

and about 18% remain asymptomatic.1, 3 The clinicalseverity of the disease ranges from death in utero to

mild symptoms without physical signs in old age.2Superficial facial muscles, levator palpebral superioris,temporalis, sternocleidomastoid, distal muscles offorearm and dorsiflexors of foot are most prominentlyaffected. The atrophy of facial muscles gives typicalhatchet shaped appearance to face. Quadriceps,diaphragm, intercostals, palatal muscles, pharyngealmuscles, and extraocular muscles are also commonlyinvolved. Muscles of pelvic girdle, hamstrings,soleus, and gastrocnemius are spared.1 Smooth muscleinvolvement of gastrointestinal tract may lead todysphagia and irritable bowel syndrome like symptoms.

Fig. 1 : Clinical photograph of patient showing atrophy of facialmuscles, muscles of mastication (hatchet facies) and atrophy of

neck muscle.

Fig. 2 : Percussion myotonia in thenar muscle of hand.

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Conduction defect and cardiomyopathy denotes cardiacinvolvement. Cataract, frontal baldness in male, gonadalatrophy, hypersomnia, mild endocrinal anomalies, bonechanges and abnormalities of immunoglobulins can beother associated disorders.1-3

`Congenital form ' is evident at birth with history ofpolyhydramnios and poor fetal movement in pregnancy.

There can be respiratory and feeding difficulty inneonatal period with death of few, in those survivinguntil late teens or early adulthood, hypotonia resolvesand motor function improves but during adolescencethe features of classic adult form appear. The late onsetform' is associated with a small CTG-repeat expansionand is typically asymptomatic or oligosymptomatic.1-3Death is usually due to respiratory infections or cardiaccause.

There is currently no specific therapy. The surgicalprocedures are avoided due to associated anestheticsensitivit y, postoperativel y respiratory muscle

inadequacy with high incidence of arrhythmias. Thesepatients require regular, general, and neuromuscularassessment for detection and correction of systemicdisorders and for better quality of life. Physiotherapy,occupational advice, and speech therapy all have a

role in such patients. Genetic counseling by means ofchorionic villous sampling can be offered for screeningto the members of family affected.1-3

SK Mahajan*, BR Sood*, V Chauhan**, S Thakur***,LS Pal+*Registrar, **Post Graduate, ***Associate Professor, +Professorand Head, Department of Medicine, I. G. Medical College,Shimla (H. P.).Received : 13.10.2003; Revised : 17.8.2004; Re-revised : 1.2.2007;Accepted : 8.2.2007

REFERENCES1. Brook JD. Molecular basis of myotonic dystrophy: expansion of a

trinucleotide (CTG) repeat in the 3 end of a transcript encodinga protein kinase family member. Cell 1992;68:799-808.

2. Harper PS. Myotonic dystrophy and other autosomal musculardystrophies. In Scriver CS, Blaudet AL, Sly W S et al (Edi).The Metabolic and Molecular Basis of Inherited disease 7thEdi. Mcgraw Hill, Inc Health Profession Division New York1995;III:4227-41.

3. Hilton-Jones D. Myotonia. Oxford Textbook of Medicine. WarrelDA, Cox TM, Firth JD, et al (Edi) 4th Edi Oxford University Press.

Oxford 2003;I:480-1.

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