Dominant and recessive deafness caused by mutations of a novel gene, TMC1, required for cochlear hair-cell function.

Positional cloning of hereditary deafness genes is a direct approach to identify molecules and mechanisms underlying auditory function. Here we report a locus for dominant deafness, DFNA36, which maps to human chromosome 9q13-21 in a region overlapping the DFNB7/B11 locus for recessive deafness. We identified eight mutations in a new gene, transmembrane cochlear-expressed gene 1 (TMC1), in a DFNA36 family and eleven DFNB7/B11 families. We detected a 1.6-kb genomic deletion encompassing exon 14 of Tmc1 in the recessive deafness (dn) mouse mutant, which lacks auditory responses and has hair-cell degeneration. TMC1 and TMC2 on chromosome 20p13 are members of a gene family predicted to encode transmembrane proteins. Tmc1 mRNA is expressed in hair cells of the postnatal mouse cochlea and vestibular end organs and is required for normal function of cochlear hair cells.

Characterisation of mutations and genotype-phenotype correlation in cystic fibrosis: experience from India.

BACKGROUND: Very little is known about the genetics of cystic fibrosis (CF) from the Indian subcontinent. The aims of the study were to identify the mutations and study the relation of genotype with phenotype in Indian children with CF. METHODS: A total of 100 patients with CF were screened for mutations in the CFTR gene. These included c.1521_1523delCTT (p.F508del) and c.3849+10 kb C>T mutations followed by single strand conformation polymorphism/heteroduplex analysis for mutations in 19 out of 27 exons of the CFTR gene. RESULTS: At least one mutation was identified in 40 patients. The most common mutation identified was p.F508del; 20 patients were homozygous and 13 heterozygous. In addition, c.3849+10 kb C>T, c.1161delC, and p.S549N were identified in two patients each and p.R352Q, p.R1158X and p.R75Q were identified in one patient each. Three novel mutations, viz. c.1002-7_1002-5delTTT, p.G149X and p.L183I were also identified. Majority of patients who were p.F508del positive originated from Pakistan and north-western states of India. The phenotypes of all patients were classical. Genotype-phenotype correlation revealed that p.F508del positive patients had a more severe disease, manifesting at an earlier age. CONCLUSIONS: A strategy for mutation screening for CF in India must involve testing for p.F508del followed by c.1161delC, c.3849+10 kb C>T and p.S549N. There is a need for large multicentric studies using more sensitive techniques for the identification of mutations in Indian CF patients.

Central diabetes insipidus: clinical profile and factors indicating organic etiology in children.

OBJECTIVE: To evaluate the profile of children with central diabetes insipidus (DI) and identify factors indicating organic etiology. DESIGN: Retrospective chart review. SETTING: Tertiary referral hospital. SUBJECTS: Fifty-nine children with central DI (40 boys, 19 girls). METHODS: Features of organic and idiopathic central DI were compared using students t test and chi square test. Odds ratio was calculated for factors indicating organic etiology. RESULTS: Diagnosis included post-operative central DI (13, 22%), central nervous system (CNS) malformations (5, 8.6% holoprosencephaly 4 and hydrocephalus 1), histiocytosis (11, 18.6%), CNS pathology (11, 18.6%; craniopharyngioma 3, empty sella 2, germinoma 2, neuro-tuberculosis 2, arachnoid cyst 1 and glioma 1) and idiopathic central DI (19, 32.2%). Children with organic central DI were diagnosed later (7.8+/- 3.1 years against 5.3+/-2.4 years, P=0.03) and had lower height standard deviation score (-2.7+/-1.0 versus -1.0+/- 1.0, P<0.001) compared to idiopathic group. A greater proportion of children with organic central DI had short stature (81.8% against 10.5%, P <0.001, odds ratio 38.25), neurological features (45.5% against 0%, p 0.009) and anterior pituitary hormone deficiency (81.8% against 5.3%, P<0.001, odds ratio 81) compared to idiopathic group. A combination of short stature and onset after five years of age led to discrimination of organic central DI from idiopathic group in all cases. CONCLUSION: Organic central DI should be suspected in children presenting after the age of five years with growth retardation and features of anterior pituitary deficiency.

Growth pattern and final height in 21-hydroxylase deficiency.

Growth pattern and final height were evaluated in 47 children with 21-hydroxylase deficiency to identify factors influencing growth. The subjects were followed-up from the age of 0.6 +/- 1.2 years for 8.8 +/- 3.9 years. Final height SDS was significantly below target height SDS (- 2.5 +/- 1.4 versus - 1.0 +/- 1.0, P < 0.001). Laboratory monitoring and type of disease (salt-wasting or simple virilizing) significantly influenced age-specific height SDS. Age at treatment, frequency of laboratory monitoring and dose of glucocorticoid during infancy influenced final height on univariate analysis; the effect was not sustained on multivariate analysis. Our study emphasizes the need for regular laboratory monitoring and lower glucocorticoid dose during infancy in 21-hydroxylase deficiency.

Serum leptin levels in obese Indian children relation to clinical and biochemical parameters.

OBJECTIVE: To evaluate serum leptin levels in obese Indian children and its correlation to anthropometric and biochemical parameters. DESIGN: Cohort study. SETTING: Referral tertiary hospital. METHODOLOGY: Leptin levels were measured in 36 children (26 boys, age 1.5 to 15 years) and 37 adults (21 men, age 25 to 69 years) with obesity and 29 normal weight controls (15 children and 14 adults). RESULTS: Leptin levels were higher than controls in obese children (19.4 +/- 6.4 ng/mL against 5.4 +/- 1.7 ng/mL, p = 0.0001) and obese adults (18.9 +/- 6.4 ng/mL against 7.8 +/- 5.6 ng/mL, p = 0.0001). Leptin levels were higher than males in obese girls (23.5 +/- 1.7 ng/mL against 18.0 +/-7.6 ng/mL, p = 0.040) and women (21.3 +/- 4.4 ng/mL against 15.8 +/- 7.4 ng/mL). Leptin levels correlated with body mass index, waist circumference and waist to-hip ratio. A positive correlation was observed between serum leptin and cholesterol, triglycerides and LDL-cholesterol. No correlation was seen with fasting blood glucose and HDL-cholesterol. CONCLUSIONS: Leptin levels correlate significantly with anthropometric and laboratory parameters in obese children. There is a need for further studies on the role of leptin in childhood obesity and metabolic syndrome.

Combination growth hormone and gonadotropin releasing hormone analog therapy in 11beta-hydroxylase deficiency.

Diagnosis of 11beta-hydroxylase deficiency was made in a boy at the age of 2 1/2 years on the basis of peripheral precocious puberty, growth acceleration (height standard deviation score +4.4) with advanced skeletal maturation (bone age 8.4 years) and elevated deoxycortisol levels. Glucocorticoid supplementation led to normalization of blood pressure but was associated with progression to central precocious puberty and increase in bone age resulting in decrease in predicted adult height to 133.7 cm (target height 163 cm). The child was started on GnRH analog (triptorelin 3.75 mg every 28 days), which led to improvement in predicted adult height by 3.1 cm over 15 months. Addition of growth hormone (0.1 IU/kg/day) resulted in improvement in predicted adult height (151 cm) and height deficit (12 cm) over the next 3.6 years. Final height (151 cm) exceeded predicted height at the initiation of GnRH analog treatment by 17.3 cm. This report suggests that combination GH and GnRH analog treatment may be useful in improving height outcome in children with 11beta-hydroxylase deficiency and compromised final height.

Ovarian cysts in young girls with hypothyroidism: follow-up and effect of treatment.

Ovarian cysts have been reported in girls with longstanding uncompensated primary hypothyroidism. Restoration of euthyroid state has been associated with resolution of these cysts; long-term follow-up of these patients is however lacking. We evaluated the outcome in ten girls with ovarian cysts and hypothyroidism managed at our hospital with special emphasis on subsequent pubertal development and ovarian imaging. Patients were diagnosed at the age of 8.6 +/- 2.3 years (mean +/- SD) with severe uncompensated primary hypothyroidism (TSH levels >100 mIU/l in all; 509.3 +/- 651 mIU/l) and growth retardation (height SDS -4.1 +/- 1.8). Nine girls had vaginal bleeding at diagnosis; five also had thelarche. LH and FSH levels were prepubertal in all patients. Ovarian cysts were bilateral in eight girls (80%); internal septation was noted in six. Thyroxine replacement (4.1 +/- 0.7 microg/kg/day) led to normalization of TSH levels with reversal of pubertal changes and regression of ovarian cysts in all patients 2.2 +/- 1.0 months after treatment. At last follow-up 3.5 +/- 2.6 years after initiation of treatment at the age of 12.0 +/- 2.3 years, all patients had normal ovarian size in ultrasound evaluation with six girls progressing to normal puberty. Our study emphasizes the need to exclude hypothyroidism in young girls with ovarian cysts. Identification of hypothyroidism in these girls obviates the need for extensive investigations.

Growth pattern and skeletal maturation following growth hormone therapy in growth hormone deficiency: factors influencing outcome.

OBJECTIVE: To evaluate pattern of growth and skeletal maturation following growth hormone (GH) therapy in children with GH deficiency (GHD) with special emphasis on factors influencing outcome. METHODS: Records of ninety-six children (67 boys, 29 girls) with GHD treated with GH for 2.3 +/-2.1 years were reviewed. RESULTS: Height SDS at the end of treatment was significantly higher than that at initiation (-3.4 +/- 1.7 versus -4.8 +/-1.6, P < 0.001); it was however lower than target height SDS (corrected height SDS (1.8 +/- 1.6, P < 0.001). The greatest increase in height SDS was observed during the first two years of treatment. Kaplan Meier survival analysis showed that 92%; of all subjects achieving end height SDS in the target height range did so within the first two years of treatment. Height SDS for bone age increased by 0.7 +/-0.9 during treatment (from -2.5 +/- 1.0 to -1.8 +/- 1.5, P < 0.001); the increase was however lower compared to that for height SDS for chronological age (P < 0.01) suggesting inadvertent skeletal maturation. End height SDS was influenced by duration of treatment and corrected height SDS on multivariate analysis. CONCLUSION: GH treatment improves growth parameters in GHD; height however still remains compromised. Most of the catch-up growth occurs within two years of treatment emphasizing the need of optimal treatment during this period. Inadvertent skeletal maturation during treatment indicates a need for evaluating the role of agents effective in retarding skeletal maturation.

Fetal Hyperthyroidism: Intrauterine Treatment with Carbimazole in Two Siblings.

Hyperthyroidism can manifest very early in fetal life (fetal thyrotoxicosis) or immediately after birth (neonatal thyrotoxicosis). The authors describe outcome of pregnancies in a woman with Graves' disease who received medical management and underwent subtotal thyroidectomy. The first pregnancy resulted in macerated stillbirth at 32 wk. Fetal tachycardia was followed by intrauterine death at 30 wk in the second pregnancy and macerated stillbirth at 26 wk in the third pregnancy. Fetal tachycardia was detected at 17 wk in the fourth pregnancy. Treatment with carbimazole along with thyroxine was followed by a live birth at 35 wk; but the baby developed severe fatal neonatal thyrotoxicosis with crisis on day 9 and died on day 12. Fetal tachycardia was noted in the fifth pregnancy as well and she was treated with carbimazole and thyroxine. She delivered a male baby at 37 wk. He developed neonatal hypothyroidism on day 8 which was controlled with thyroxine.

Hypothalamic hamartoma, gelastic epilepsy, precocious puberty--a diffuse cerebral dysgenesis.

Childhood epileptic syndrome characterized by early onset gelastic seizures, hypothalamic hamartoma and precocious puberty is well recognized though rare. We report association of agenesis of corpus callosum, Dandy-Walker complex and heterotopic gray matter with this childhood epileptic syndrome which is hitherto an unreported association. The child showed a satisfactory response to gonadotropin releasing hormone agonist.

CNS germinoma in a boy with simple virilizing 21-hydroxylase deficiency and precocious puberty.

A 6 year-old boy presented with peripheral precocious puberty and was diagnosed as having simple virilizing 21-hydroxylase deficiency based on clinical features and elevated 17-hydroxyprogesterone levels on ACTH stimulation. He was managed with glucocorticoids and mineralocorticoids. Two years later he presented with features of CNS involvement in the form of seizures and raised intracranial pressure with rapid progression of puberty. Contrast enhanced CT scan of brain showed an intraventricular tumor with cerebrospinal fluid cytology suggestive of germinoma. Serum and CSF levels of human chorionic gonadotropin (hCG) and alphafetoprotein (AFP) were elevated, confirming the diagnosis of germinoma.

Precocious puberty: clinical and endocrine profile and factors indicating neurogenic precocity in Indian children.

The objective of this study was to evaluate the clinical and endocrine profile of patients with precocious puberty followed up in a tertiary care hospital. Records of 140 patients (114 girls, 26 boys) with precocious puberty were reviewed. Clinical features including age of onset, stage of pubertal development, presenting symptoms, features suggestive of CNS involvement and family history were analyzed. Endocrine investigations included basal and GnRH-stimulated levels of LH and FSH as well as 17OHP, DHEA, hCG and thyroid profile. Abdominal and pelvic ultrasonography and CNS imaging were correlated with clinical features. Girls outnumbered boys in this series (4.4:1). Neurogenic central isosexual precocious puberty (CIPP) was more common in boys (10 out of 18, 55.6%) than girls (16 out of 77, 20.8%). The most common cause of neurogenic CIPP was hypothalamic hamartoma present in five girls and four boys. Other causes of neurogenic CIPP included neurotuberculosis, pituitary adenoma, hydrocephalus, post radiotherapy, CNS tumors and malformations. Peripheral precocious puberty (PPP) was secondary to adrenal causes in boys and ovarian cysts in girls. Benign variants of precocious puberty, such as premature thelarche and premature adrenarche, were present in 23 and six girls, respectively. Hypothyroidism was present in four girls and McCune-Albright syndrome in one girl. Girls with neurogenic CIPP had a lower age of onset as compared to idiopathic CIPP (3.6 +/- 2.7 years vs 5.4 +/- 2.5 years, p = 0.014). The lowest age of onset was seen in girls with hypothalamic hamartoma (1.6 +/- 0.9 years). Forty-seven girls with CIPP (seven neurogenic and 40 idiopathic) presented after the age of 6 years. Features of CNS involvement, in the form of seizures, mental retardation, raised intracranial tension or focal neurological deficits, were present in seven girls (43.8%) and four boys (40%), and gelastic seizures were present in three children. Girls with CIPP had greater bone age advancement (3.4 +/- 1.5 years) and negative height standard deviation for bone age (-2.7 +/- 1.5) than those with PPP (1.9 +/- 1.6 years and -1.3 +/- 1.3) and premature thelarche (0.4 +/- 0.4 years and -0.8 +/- 0.8). Patients with neurogenic CIPP had significantly higher levels of baseline and GnRH-stimulated levels of LH and FSH and LH:FSH ratio than those with idiopathic CIPP. Occurrence of neurogenic CIPP in seven girls with an age of onset after 6 years emphasizes the need for CNS imaging in these girls contrary to the current recommendations. The fact that 65.6% cases of idiopathic CIPP presented after the age of 6 years raises the possibility that these patients may be physiological variants of normal puberty. Pointers to neurogenic CIPP included early age of onset in girls, clinical features of CNS involvement, and elevated basal and stimulated LH levels and LH:FSH ratio.

Rathke's cleft cyst: missed etiology of panhypopituitarism in presence of coexistent ocular and neurocysticercosis.

We report a 10 year-old girl with panhypopituitarism and coexistent ocular and neurocysticercosis. Intrasellar cystic lesions whether neoplastic or non-neoplastic in origin are often difficult to distinguish because their symptoms, signs, and radiological characteristics are similar. The diagnosis of intrasellar cysticercosis was initially considered because of high endemicity, positive serology for cysticercus and radiological evidence of cysticercosis in the eye and parietal lobe. However, since there was no improvement with cysticidal therapy and no radiological resolution of the sellar lesion, surgery was performed, which revealed a Rathke's cleft cyst.

Rapid prenatal karyotyping using foetal blood obtained by cordocentesis.

BACKGROUND: Prenatal karyotyping using foetal blood samples obtained by cordocentesis is a useful method of detecting abnormal chromosomes in the foetus. METHODS: Cordocentesis was performed in 187 cases for prenatal karyotyping between January 1995 and September 2000. Pregnant women were between 18 and 38 weeks of gestation and their ages ranged from 18 to 40 years. The common indications were ultrasonographic abnormalities (47.6%), history of previous Down syndrome (13.3%), advanced maternal age (11.7%), low maternal serum alpha foetoprotein levels (10.7%), previous child with malformation (10.7%), previous child with trisomy (chromosome 13/18) (2.6%), parent a balanced translocation carrier (1.6%) and high maternal serum alpha foetoprotein levels (1.6%). RESULTS: Analysis of 137 successful cultures showed 8 (5.2%) karyotype abnormalities. The remaining samples could not be reported due to the presence of maternal contamination of the sample (12.3%), inadequate sample (6.4%) or culture failure (9.8%). In those with an abnormal karyotype, obstetric management could be altered appropriately. CONCLUSION: In foetuses at high risk of a chromosomal aberration, a rapidly obtained karyotype is helpful in obstetric management.

Familial hypercholesterolemia.

Abnormalities in the lipid profile though uncommon in pediatric practice pose an increased risk for developing heart disease. Studies suggest that adult cardiovascular disease has its roots in children and young adults. A significant correlation between atherosclerotic changes in children and young adults and total and LDL cholesterol levels also exists. The association is particularly true for Familial Hypercholesterolemia. We report a young boy aged 14 years who presented with all the features of Familial Hypercholesterolemia.

21-Hydroxylase deficiency: clinical features, laboratory profile and pointers to diagnosis in Indian children.

We evaluated clinical features, laboratory profile and pointers to diagnosis of 21-hydroxylase deficiency in children presenting to the Pediatric Endocrine Clinic of our hospital from 1990 to 2002. Of the 94 patients included in the study 46 had salt wasting form (SW, 21 girls), 44 simple virilizing form (SV, 34 girls) and 4 non-classical form of the disease (NC, all girls). No difference was observed in the mean (95% confidence interval) age at diagnosis in boys and girls with salt wasting (2.3 mo (0.7-3.9 mo) against 1.3 mo (0.9-1.7 mo), p not significant) despite the presence of genital ambiguity in all girls at birth. Diagnosis of salt wasting was missed at admission in 18 boys (72%) and 3 girls (14.3%) highlighting the need for high index of suspicion for the disorder. Eight patients with 46 XX karyotype (14.5%) had male-like external genitalia with cryptorchidism emphasizing the need for evaluation of boys with cryptorchidism for female pseudohermaphroditism. Our study reiterates the need for early recognition and management of 21-hydroxylase deficiency in children in countries where neonatal screening programs are not feasible.

Long-acting GnRH analogue triptorelin therapy in central isosexual precocious puberty.

OBJECTIVE: To evaluate the efficacy of long acting GnRH analogue in improving the auxological outcome of patients with central isosexual precocious puberty (CIPP) and to determine the factors influencing the response. METHODS: Thirty-five patients (30 girls, 5 boys) with CIPP were treated with a long acting GnRH analogue, triptorelin. Final height outcomes and factors affecting treatment were analyzed. RESULTS: Treatment was started at the chronological age (CA) of 6.5 1.8 years in girls and 4.4 1.5 years in boys and continued for a period of 3.7 1.8 years in girls and 6 1.8 years in boys. Follow-up period after discontinuation of treatment was 2.2 0.5 years in girls and 2.6 0.3 years in boys. Treatment led to regression of precocious puberty and reversal of secondary sexual characteristics. There was decline in growth rate reflected by a fall in heightSD of 0.8 0.8 in girls and 2.3 0.9 in boys (p = 0.014), an even greater retardation in bone age (BA) advancement with a decrease in BA-CA of 1.7 1 years in girls and 2.7 1 years in boys and a fall in heightSDBA of 1.5 1.1 in girls and 2.1 1.6 in boys. Final height (149.8 6.9 cm in girls and 161.9 3.9 cm in boys) exceeded projected height at the onset of treatment (143.4 8.3 cm in girls and 154.3 2.7 cm in boys) by 6.4 2.4 cm in girls and 7.6 1.5 cm in boys ( p < 0.001 in both the groups). Factors influencing height gain included age at start of therapy (r = 0.715), BA-CA at the time of initiation of treatment (r = 0.734), heightSDBA at the onset of treatment ( r = 0.566) and the duration of treatment (r = 0.711). Girls treated at an age of less than 6 years (n = 9) had a greater height gain (8.7 1.6 cm versus 5.3 1.9 cm, p < 0.001) and achieved similar final height (148.7 8 cm versus 150.2 6.6 cm) in those treated after this age (n = 21). No side effects of GnRH therapy were observed in the study. CONCLUSION: Long acting GnRH therapy is effective in improving the auxological outcome of patients with CIPP. Maximum benefit is observed in girls with greater bone age advancement treated at a younger age and for a longer duration of treatment. These girls had lower bone age advance at discontinuation of treatment.

Precocious puberty--perspectives on diagnosis and management.

The term 'precocious puberty' signifies the onset of secondary sexual characters before the age of 9 y in boys and 8 y in girls. Menarche before 9.5 y is also considered precocious. These definitions are constantly evolving due to the secular trends observed all over the world. It is crucial to decide whether the child has central (gonadotropin-dependent, GDPP) or peripheral (gonadotropin-independent, GIPP) form of precocious puberty. Some benign conditions such as premature thelarche and premature pubarche may mimic precocious puberty. A systematic approach with detailed history and clinical examination helps to arrive at a diagnosis in most cases. An underlying neurologic disorder is more likely in a very young boy. Basal LH level is the best screening test to diagnose GDPP. LH level less than 0.1 IU/L by a very sensitive assay indicates prepubertal stage. Stimulation tests using gonadotropin releasing hormone (GnRH) or its analog (GnRHa), leuprolide help to confirm the diagnosis of GDPP. High resolution MRI of brain helps to detect abnormalities in hypothalamus and pituitary region. GnRH analogs (GnRHa) are the only effective treatment for GDPP at present. In girls, breast size may regress; menses ceases and vaginal mucosa becomes non-estrogenized. In boys testicular volumes remain static or decrease and genital growth regresses. The effects of GnRH analogs are reversible on discontinuation of therapy, with restoration of normal function within 3 mo after stopping treatment. Treatment of GIPP however is far from satisfactory.

Contemporary issues in precocious puberty.

Precocious puberty poses significant diagnostic and therapeutic challenge to the physician. Recent advances in the understanding of pathophysiology of precocious puberty have resulted in improved management. Timely intervention is mandatory to achieve successful outcome. The identification of critical role of KISS-1-kisspeptin-GPR54 system has gone a long way to provide an insight into pubertal physiology. It is likely that the system would become an important diagnostic and therapeutic target in children with precocious puberty. Epidemiological studies point toward earlier thelarche. This is, however, associated with slower progression as the age of menarche is static. These changes have led to suggestions of lowering the age cutoffs for precocious puberty in girls. New developments in assessment of precocious puberty including gonadotropin releasing hormone (GnRH) agonist test have made characterization of precocious puberty easier. Longstanding GnRH analogs have become the mainstay of treatment of gonadotropin-dependent precocious puberty, while aromatase inhibitors and inhibitors of sex hormone action are increasingly being used in gonadotropin-independent precocious puberty.