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Editor,—Cases with symptomatology similar to one described by von Schenck et al 1 have been amply reported in Indian literature under “infantile tremor syndrome”,2 a term very familiar to the paediatricians of the region. Following its first description in 1957 by Dikshit,3 many more such patients were described in subsequent years.2 The syndrome, affecting exclusively breast fed infants from low socioeconomic conditions, is characterised by a constellation of neurological, haematological, and skin changes. Affected infants, though plump and chubby, are frequently subnormal in weight and stature. Neurological symptoms include apathy, lethargy, expressionless face, hypotonia, developmental retardation/arrest, and later regression. Involuntary movements, usually tremors, often supervene abruptly in a majority of the cases. The cry is peculiar (high pitched and tremulous). Skin hyperpigmentation, most marked over dorsum of hands and feet contrasts with the generalised pallor of anaemia. Hair is often sparse and depigmented. Documented vitamin B-12 deficiency, megaloblastosis, and therapeutic response to vitamin B-12 administration has been observed in some but not all patients.4 5 It is also suggested that megaloblastosis is a late feature of the syndrome.5 In other instances deficiency of other vitamins or minerals has been implicated, though the therapeutic response to supplementation has been poor.2 The condition is self limited and recovery almost always occurs.2
Only a small number of cases have been described from developed countries, occurring solely in vitamin B-12 deficient exclusively breast fed infants, whose mothers had unrecognised pernicious anaemia or who were strict vegetarians. Response to treatment with vitamin B-12 in such cases was often dramatic.4-6 Therefore the term infantile tremor syndrome defines a broader group of infants with similar neurohaematological symptomatology, which in some cases is due to vitamin B-12 deficiency.