Mutation Analysis of Indian Patients with Urea Cycle Defects.

Molecular testing for a specific metabolic disorder remains the gold standard due to its high specificity and sensitivity and possibility of accurate prenatal diagnosis. We report four cases of urea cycle defect where mutational analysis of the involved genes was performed and subsequently, prenatal diagnosis could be offered to one of the family.

Recombinant Macrophage Targeted Enzyme Replacement Therapy for Gaucher Disease in India.

Objective: Gaucher disease in India has been reported only in a few case reports from India. The aim of the study was to assess the response to enzyme replacement therapy in Indian patients with Gaucher disease. Design: Retrospective analysis of patients receiving CHO-derived recombinant macrophage-targetted glucocorebrosidase. Setting: Five centers from India with experience in treating lysosomal storage disorders. Patients: The diagnosis of Gaucher disease was confirmed by low glucocerebrosidase levels, though it was first made on splenectomy in 8 and on bone marrow examination in 9 patients. Twenty five of 52 patients diagnosed with Gaucher disease (17 Type I, 8 mild Type III) received treatment for >6 months. Indications for treatment included symptomatic anemia, thrombocytopenia, organomegaly, bone disease or mild neurological symptoms leading to impairment of quality of life. Patients with significant neurological involvement were excluded. The drug infusions were given intravenously every 15 days. Main Outcome measures: Hemoglobin, platelet counts, liver and spleen volumes and growth parameters. Results: 22 of the 25 children who survived were analyzed. After 6 months of treatment, the mean (range) increase in hemoglobin was 1.5 (-3.4 to 6.1) g/dL (P=0.01) and in platelet count was 32 x 109/L (-98.5 x 109 to 145.5 x109) /L (P=0.02). The mean (range) increase in weight was 3 kg (-5.6 to 10.5) (P=0.04) and in height was 7.1 cm (0 to 26.5) (P=0.0003). Liver size decreased by a mean (range) of 38.5% (- 5.5 to 86.7) (P=0.0003) and the spleen size by 34.8% (0 to 91.7) (P=0.004). All patients had improvement in bone pains and in 2 patients, neurological symptoms improved with others remaining static. Conclusions: This is the first reported cohort of patients in India reporting our experience with imiglucerase enzyme replacement therapy for treatment of Gaucher Disease in India.

Cord blood analysis for prenatal diagnosis of thalassemia major and hemophilia A.

Beta thalassemia and Hemophilia A are common genetic disorders for which prenatal diagnosis (PND) is an accepted option. Our aim was to evaluate cord blood analysis as a method for PND of these disorders. Cord blood samples at 18-26 weeks gestation from nine mothers with previous thalassemia major child and five families with previous hemophilia A were studied. In the former; HbF, HbA2 and HbF were determined by high performance liquid chromatography (HPLC) and in latter; Factor VIII and IX assays were done by one stage method. In HPLC studies for thalassemia, three out of nine fetuses were affected, five were carriers and one was normal. In hemophilia PND samples, 2 out of five fetuses were affected. Thus, HPLC and factor VIII assay in cord blood are feasible alternatives for PND in Beta thalassemia and hemophilia A respectively, especially when DNA analysis is uninformative or there are financial constraints.

Cytogenetic causes for recurrent spontaneous abortions - An experience of 742 couples (1484 cases).

BACKGROUND: First trimester pregnancy loss is a very common complication and a matter of concern for couples planning pregnancy. Balanced chromosomal rearrangements in either parent is an important cause of recurrent pregnancy loss particularly in the first trimester. AIMS: In this study an evaluation of the contribution of chromosomal anomalies in causing repeated spontaneous abortions was made. METHODS AND MATERIALS: A review of the cytogenetic data in 742 couples (1484 individuals) with recurrent spontaneous abortions who were examined for chromosomal aberrations in the period 1990-2003 is presented. Women who had at least two abortions, or spontaneous abortions preceded or followed by fetal deaths or birth of a malformed child, and patients who had recurrent spontaneous abortions (> 3) with normal live issue/s were studied. RESULTS: Chromosomal rearrangements were found in 31 individuals (2%). These abnormalities included 22 (2.9%) structural aberrations, 9 (1.2%) numerical anomalies. In addition to these abnormalities, 21 (3.2%) chromosomal variants were also found. CONCLUSION: Chromosomal analysis is an important etiological investigation in couples with repeated spontaneous abortions as it helps in genetic counseling and deciding about further reproductive options.

Can throat swab after physiotherapy replace sputum for identification of microbial pathogens in children with cystic fibrosis?

OBJECTIVE: To compare cultures throat swab after physiotherapy with results of sputum culture in identification of lower airway pathogens in children with cystic fibrosis. METHODS: 387 samples of sputum cough swabs, throat swab and throat swab after physiotherapy were collected from 48 patients of cystic fibrosis and cultured for aerobic bacteria. The results of cultures of cough swabs, throat swab and throat swab after physiotherapy were compared with results of sputum culture. RESULTS: There was good concordance between culture results of sputum and other methods. Over all concordance was 70%, 81% and 92% with cough swab, throat swab and throat swab after physiotherapy. Sensitivity for isolation of Pseudomonas aeruginosa by throat swab, cough swab and throat swab after physiotherapy was 40%, 42% and 82% respectively. Specificity for isolation of Pseudomonas by throat swab, cough swab and throat swab after physiotherapy was 99%, 100% and 99% respectively. Sensitivity for isolation of Staphylococcus aureus by throat swab, cough swab and throat swab after physiotherapy was 57%, 50% and 100% respectively. Specificity for isolation of Staphylococcus by throat swab, cough swab and throat swab after physiotherapy was 99% for all these methods. CONCLUSION: It is concluded that throat swab after physiotherapy in a child with CF can be used reliably for identification of lower airway pathogens.

An indigenously developed method for sweat collection and estimation of chloride for diagnosis of cystic fibrosis.

An indigenously developed method for sweat collection and titration method for estimation of chloride was validated. The mean difference in estimated chloride value from the known strength of saline in 50 samples was -1.04 +/- 4.13 mEq/L (95% CI: -0.07 to 2.28). The mean difference in the estimated chloride values between two observers when the test was performed on known strengths of saline solution was -2.5 +/- 4.24 mEq/L (95% CI: -3.67 to 1.33). The inter observer variability between two observers when the test was performed on sweat samples obtained from 50 individuals was -1.12 +/- 4.34 mEq/L (95% CI: -2.23 to 0.8 ). Sweat weight of more than 100 mg could be collected in first attempt in 602 of 757 (80%) patient with an average sweat weight of 230 mg. This inexpensive method of sweat collection and chloride estimation has acceptable accuracy and repeatability and can be used in resource poor setting for making a diagnosis of cystic fibrosis.

Congenital adrenal hyperplasia presenting as hematuria and acute renal faliure.

We present a neonate who presented with hematuria and acute renal failure. Classical 21 hydroxylase deficiency was diagnosed on the basis of features of salt wasting, response to treatment with corticosteroids and mineralocorticoids and a positive ACTH stimulation test. Renal vein thrombosis secondary to hemoconcentration due to salt wasting was attributed as the cause of hematuria. Follow-up revealed clinical improvement and normalization of renal parameters. This is the first report of congenital adrenal hyperplasia presenting as hematuria and renal failure to the best of our knowledge.

Spectrum of floppy children in Indian scenario.

OBJECTIVE: To study the clinical profile of paralytic floppy infants undertaking available investigations and detect the frequency of exon7 of survival motor neuron (SMNT) gene deletion among the spinal muscular atrophy (SMA) cases. DESIGN: Descriptive study. SETTING: Tertiary care teaching hospital. SUBJECTS: 70 paralytic floppy infants (40 males/30 females) with age less than 13 years were included in the study. Exclusion criteria included central hypotonia of any cause. Detailed clinical evaluation was done followed by serum creatine phosphokinase levels, electrophysiological studies, muscle biopsy including immunohistochemistry and electron microscopy. Exon7 of SMNT gene deletion studies was done by PCR. RESULTS: Final diagnosis of SMA was assigned to 37 patients followed by congenital myopathy (n = 7), cogenital muscular dystrophy (n = 5), mitochondrial myopathy (n = 4), neuropathies (n = 5) and diaphragmatic SMA (n = 1). Only 15.7% of cases remained unclassified. When EMG was correlated with final diagnosis, it was 80.6% and 75% sensitive and 68.8% and 87.5% specific for neurogenic and muscle disease, respectively. Muscle biopsy revealed neurogenic atrophy in 47.8% cases followed by normal in 37.3% and myopathic pattern in 14.97% cases. Exon7 of SMNT gene was deleted in only 50% of SMA cases. CONCLUSIONS: Spinal muscular atrophy was the commonest cause of floppy children. The low rate of SMNT gene deletion detected needs confirmation with further studies.

Prenatal diagnosis of haemoglobinopathies.

BACKGROUND: Haemoglobinopathies constitute a major health problem in the Indian subcontinent. In the absence of any method for achieving complete cure and treatment being expensive, prenatal diagnosis and selective termination of an affected foetus is a feasible option to decrease the disease load. We report our experience with prenatal diagnosis of haemoglobinopathies over a two-and-a-half year period in 257 pregnancies. MEHODS: Amplification refractory mutation system (ARMS) was used to detect beta-thalassaemia, haemoglobin E and sickle cell mutations. RESULTS: Five mutations in the beta-globin gene which are common in the Indian population were detected in 92.3% of mutant chromosomes, whereas 3.1% of chromosomes carried rare mutations followed by 0.8% haemoglobin E and 0.4% sickle cell mutations. Mutations in 3.3% chromosomes were uncharacterized. The prenatal procedure, carried out early in pregnancy, was a chorionic villus sampling in most cases. A confirmed diagnosis based on ARMS-PCR was given in 241 (93.8%) cases. In 10 cases (3.9%) linkage analysis was required to confirm the foetal status, as mutations in both parents were not identified or the chorionic villus sample carried the single identified mutation. Four families with haemoglobin E-beta thalassaemia and one family with sickle cell disease were also included. Of the study population, 91.25% of the couples had a previous child with haemoglobinopathy, whereas 8.75% of the couples came before the birth of the first affected child. CONCLUSION: We conclude that ARMS-PCR is a highly sensitive technique for detecting mutations in the beta-globin gene and its efficacy in the prenatal diagnosis of haemoglobinopathies is proven.

Adhalin deficiency: an unusual cause of muscular dystrophy.

Childhood muscular dystrophies have a wide clinical spectrum, motor disability and are variably inherited. Although the phenotype may appear similar they may represent distinct genetic entities. Advances in immunohistochemistry, gene deletion and linkage studies have enabled precise characterization. We report a family with an early onset weakness and calf pseudo hypertrophy in 2 male sibs with an usually mild course. Deletion screening was negative for 24 exons of the DMD gene in both. Muscle immunohistochemistry revealed normal dystrophin I and II staining but complete absence for adhalin, a dystrophin associated glycoprotein. Classifying them as adhalinopathy. Severe childhood autosomal recessive muscular dystrophies (SCARMD) result from mutation in the sarcoglycan complex (59). Adhalinopathy is now used to describe SCARMD. The adhalinopathy described in our patients is the first report from India.

Congenital myotonic dystrophy.

Myotonic muscular dystrophy is the most frequent autosomal muscular dystrophy affecting adults and children. It affects multiple organ systems and is probably the best example of variable expressivity in a human disease. This article presents a patient with congenital myotonic dystrophy who had facial dysmorphism, hypotonia, talipes, feeding and respiratory difficulties in the neonatal period and later presented to us with developmental delay and had percussion myotonia. His mother had clinical and electrophysiological features of myotonia. Expansion of unstable CTG trinucleotide repeat in the myotonic protein kinase gene was demonstrated in both. The identification of this molecular defect allows its specific diagnosis in relation to other neuromuscular disorders as well as accurate prenatal diagnosis.

Mitochondrial myopathy presenting as ataxia with dilated cardiomyopathy.

Mitochondrial disorders are multisystem diseases with very heterogeneous clinical manifestations. Common cardiac features include cardiomyopathy and conduction defects. We report a five-year-old boy who presented with signs of congestive cardiac failure and was diagnosed to have dilated cardiomyopathy. Six months later, he developed progressively worsening ataxia, hypotonia, other cerebellar signs, hearing loss, severe sensory peripheral neuropathy and lactic acidosis. Electronmicroscopy of skeletal muscle biopsy was consistent with mitochondrial myopathy.

Hypocalcemic heart failure masquerading as dilated cardiomyopathy.

Hypocalcemia is a rare, but reversible, cause of congestive heart failure. We report a 4-month-old boy diagnosed as dilated cardiomyopathy who had prolonged QoTc with low blood levels of calcium, normal phosphate, elevated alkaline phosphatase and findings suggestive of rickets. In view of non response to calcium and vitamin D3, a possible diagnosis of VDDR I (Vitamin D-dependent rickets) was made and he was treated with calcium and calcitriol. The serum calcium levels normalised within 10 days, along with resolution of the signs and symptoms of heart failure, near normal left ventricular function and normalisation of QoTc. Pediatricians should be aware of the association of hypocalcemia with cardiac dysfunction and should keep it as a possible reversible cause of heart failure in children.

Diagnosis and management of congenital adrenal hyperplasia: clinical, molecular and prenatal aspects.

Congenital adrenal hyperplasia (CAH) is the most common cause of female pseudohermaphroditism in Indian children. It is caused by enzymatic defects in the steroidogenic pathway of the adrenal glands and is characterized by impaired cortisol and aldosterone synthesis and overproduction of androgens. The disease usually presents with life-threatening problems and virilization, with long term physical and psychological effects. The clinical and laboratory diagnoses play an important role in deciding the course of treatment, which continues lifelong. To ensure proper growth and development of the patient, optimized disease management and treatment with steroids is required. Often the patient also requires surgical correction. Recent developments in molecular genetics have greatly helped in understanding the pathogenesis of the disease. The gene encoding for steroid 21-hydroxylase, CYP21, is located on the short arm of chromosome 6 in the HLA region and is amplified for genetic diagnosis. Rapid characterization of point mutations is possible using the allele-specific polymerase chain reaction technique in affected children. Counselling, prenatal diagnosis and treatment are recommended in all pregnant women with a positive family history to reduce or eliminate the effects in affected foetuses. This spares the female newborn the consequences of genital ambiguity and problems of gender identity.

Prenatal diagnosis and treatment of steroid 21-hydroxylase deficiency (congenital adrenal hyperplasia).

Steroid 21-hydroxylase deficiency congenital adrenal hyperplasia is the most common cause of genital ambiguity in females at birth. Inhibited formation of cortisol causes increase in the release of ACTH in turn leading to overproduction of adrenal androgens. This predisposes the affected female fetus to prenatal development of genital ambiguity. A large number of patients also have aldosterone insufficiency which manifests after birth in form of inability to conserve sodium and to excrete potassium which can lead to adrenal shock and neonatal death, if left untreated. Prenatal diagnosis is possible using several methods like steroid assay of amniotic fluid and, HLA typing. Recently with advancement more accurate direct molecular genetic techniques have been utilized on chorionic villus samples in first trimester of pregnancy. Prenatal treatment is also possible and pregnancies can be managed by administering dexamethasone to the mother as soon as pregnancy is diagnosed. This suppresses fetal androgen production in genetic females preventing virilization and leading to normal development. Prenatal diagnosis and treatment are highly desirable in families with a positive family history towards birth of a child without features of the disease.

Infantile-onset leukoencephalopathy with discrepant mild clinical course.

Four children characterised by megalencephaly and cerebral leukoencephalopathy with infantile onset, defined on the basis of clinical and neuroimaging findings are reported. The course of the disease is characterised by stabilization of the macrocephaly and slow clinical deterioration. The CT scan findings include supratentorial diffuse hypodensities in the white matter and swelling. The characteristic MRI findings include the discrepant severity in comparison with the clinical picture, diffuse supratentorial white matter abnormalities with subcortical cysts. The basic defect of the disease is unknown. Considering the high rate of consanguinity among the parents and the presence of two affected sibs in one family, an autosomal recessive inheritance is assumed. We report four unrelated cases of this entity.