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Chitra Prasad

Publications and source records attributed to Chitra Prasad.

12 recordsLinked to original sources
PubMed2006

CHARGE syndrome.

CHARGE syndrome was initially defined as a non-random association of anomalies (Coloboma, Heart defect, Atresia choanae, Retarded growth and development, Genital hypoplasia, Ear anomalies/deafness). In 1998, an expert group defined the major (the classical 4C's: Choanal atresia, Coloboma, Characteristic ears and Cranial nerve anomalies) and minor criteria of CHARGE syndrome. Individuals with all four major characteristics or three major and three minor characteristics are highly likely to have CHARGE syndrome. However, there have been individuals genetically identified with CHARGE syndrome without the classical choanal atresia and coloboma. The reported incidence of CHARGE syndrome ranges from 0.1-1.2/10,000 and depends on professional recognition. Coloboma mainly affects the retina. Major and minor congenital heart defects (the commonest cyanotic heart defect is tetralogy of Fallot) occur in 75-80% of patients. Choanal atresia may be membranous or bony; bilateral or unilateral. Mental retardation is variable with intelligence quotients (IQ) ranging from normal to profound retardation. Under-development of the external genitalia is a common finding in males but it is less apparent in females. Ear abnormalities include a classical finding of unusually shaped ears and hearing loss (conductive and/or nerve deafness that ranges from mild to severe deafness). Multiple cranial nerve dysfunctions are common. A behavioral phenotype for CHARGE syndrome is emerging. Mutations in the CHD7 gene (member of the chromodomain helicase DNA protein family) are detected in over 75% of patients with CHARGE syndrome. Children with CHARGE syndrome require intensive medical management as well as numerous surgical interventions. They also need multidisciplinary follow up. Some of the hidden issues of CHARGE syndrome are often forgotten, one being the feeding adaptation of these children, which needs an early aggressive approach from a feeding team. As the child develops, challenging behaviors become more common and require adaptation of educational and therapeutic services, including behavioral and pharmacological interventions.

Abnormalities, Multiple↗
PubMed2006

Congenital indifference to pain and deletion of chromosome 10q-: new association.

We describe a case of a de novo terminal deletion of the long arm of chromosome 10 with the novel feature of congenital indifference to pain in a 2-year 10-month-old boy. Relative indifference to pain defined by a lack of emotional response to pain has not been described previously in association with the terminal deletion of the long arm of chromosome 10.

Child, Preschool↗
PubMed2005

An epidemiological analysis of CHARGE syndrome: preliminary results from a Canadian study.

CHARGE syndrome is a well-characterized clinical diagnosis with recent data supporting a genetic etiology. A 3-year national surveillance coordinated by the Canadian Pediatric Surveillance Program (CPSP) was started in September 2001. Physicians notified the CPSP if they had cared for individuals with CHARGE syndrome within their practice, and then completed a detailed reporting form. To date, there are 77 confirmed cases of CHARGE syndrome. The highest provincial prevalence of CHARGE syndrome in Canada was estimated at 1 in 8,500 live births. Subgroups of cases with particular clusters of anomalies were identified. In older individuals, bilateral posterior choanal atresia (BPCA) was predictive of the presence of the three other major criteria and of aortic arch anomalies. Individuals with CHARGE syndrome who demonstrated a less extensive phenotype (<or=3 major criteria) were more likely to present with minor cardiovascular malformations, including small atrial or ventricular septal defects (VSD) or patent ductus arteriosus (PDA). A significant cause of morbidity was severe feeding difficulty, including problems with chewing, swallowing, and gastroesophageal reflux, which were prevalent throughout childhood. Infant mortality is high in individuals with CHARGE syndrome. However, life expectancy has improved for those surviving their first year. Increased mortality was associated with distinct cardiovascular malformations or ventriculomegaly combined with brainstem or cerebellar anomalies. From this study, revised diagnostic criteria are proposed for infants, children, and adolescents to help identify a group of individuals who represent CHARGE syndrome with more of the classical features as apposed to the boarder association.

Abnormalities, Multiple↗
PubMed2005

CHARGE syndrome from birth to adulthood: an individual reported on from 0 to 33 years.

CHARGE syndrome was independently reported by Hall [(1979): J Pediatr 95:395-398] and Hittner et al. [(1979): J Pediatr Ophthalmol Strabismus 16:122-128] and was initially considered to be a non-random association between distinct multiple congenital anomalies. It is now considered to be a recognizable syndrome with well-characterized diagnostic criteria and a genetic pathogenesis. We report on a 33-year-old adult male with CHARGE syndrome, with emphasis on the unique medical, behavioral, and psychological issues faced in adulthood. Characteristic facial and ear abnormalities were obvious in early childhood, and bilateral retinal colobomata, left choanal atresia, right congenital hip dislocation, and hypogonadism were diagnosed during the first year. Walking was delayed due to vestibular problems, speech was impaired due to moderately severe hearing loss, and use of sign communication was limited. Choanal atresia was surgically corrected in infancy, and atrial septal defect, ventricular septal defect, and patent ductus arteriosus were surgically corrected in childhood. Undescended testes were removed in adolescence, and gallstones were removed in early adulthood. Puberty was delayed until hormone replacement therapy began at 15 years. Behavioral disturbances and anxiety persisted throughout childhood, adolescence, and into adulthood, often resulting from communication challenges. At 33 years of age, he lives independently in a supervised group home, receives regular eye check-ups and is being monitored for severely reduced bone density.

Abnormalities, Multiple↗
PubMed2005

The floppy infant: retrospective analysis of clinical experience (1990-2000) in a tertiary care facility.

We describe the results of a retrospective study of floppy infants evaluated at the Children's Hospital of Winnipeg, a tertiary care children's facility. Cases were ascertained by a systematic search of clinical databases, hospital and electromyographic records for "floppy" infants age < 1 year, referred over a period of 11 years (1990-2000). Eighty-nine infants, 42 female (47.2%) and 47 male (52.8%), were included in the study. A definitive diagnosis was established in 60 (67.4%) cases, in 24 cases (40%) on purely clinical grounds, whereas in 36 (60%) cases, additional investigations were necessary. Karyotype, molecular diagnostics, cranial imaging, and muscle and skin biopsy provided diagnostic information. Genetic disorders in 18 of 60 (20.2%), congenital or acquired disorders of the central nervous system in 22 of 60 (24.7%), and disorders of the lower motor unit in 9 of 60 (10.1%) contributed to the majority of diagnoses. Eight of 89 (8.9%) infants died in the first year, and 2 of 89 (2.6%) were on home ventilation. Of the 61 infants surviving beyond 12 months, 38 of 61 (62.3%) were found to be globally delayed, and only 30 of 61 (49.2%) achieved independent ambulation at their last clinical evaluation. Systematic evaluation of a floppy infant followed by careful selection of investigations (karyotype, DNA-based diagnostic tests, and cranial imaging) can maximize diagnostic yield.

Female↗
PubMed2004

Heterozygous deletion of the linked genes ZIC1 and ZIC4 is involved in Dandy-Walker malformation.

Dandy-Walker malformation (DWM; OMIM #220200) is a common but poorly understood congenital cerebellar malformation in humans. Through physical mapping of 3q2 interstitial deletions in several individuals with DWM, we defined the first critical region associated with DWM, encompassing two adjacent Zinc finger in cerebellum genes, ZIC1 and ZIC4. Mice with a heterozygous deletion of these two linked genes have a phenotype that closely resembles DWM, providing a mouse model for this malformation.

Animals↗
PubMed2004

The importance of gut motility in the metabolic control of propionic acidemia.

We hypothesized that gut motility likely plays a critical role in the metabolic stability in propionic acidemia (PA). Therefore, 4 known patients with PA (aged 47 months to 185 months) were prospectively studied over 7 days in the Clinical Research Center at Children's Hospital, Boston. Determinations of ammonia, bicarbonate, and amino acids in blood; organic acids and propionylglycine in urine; and a lactulose breath test were conducted under two study conditions: on regular therapy (for 4 days) and on regular therapy plus Senekot (Purdue Frederick Company, Norwalk, Conn), an intestinal motility agent (for 3 days). The total gastrointestinal transit time was calculated using 20 nonabsorbable, inert, radio-opaque markers. The addition of an intestinal motility agent resulted in a significant decrease in blood ammonia, urinary excretion of propionylglycine, and a rise in the ratio of free to total carnitine over baseline. We concluded that enhancement of gut motility can improve metabolic stability in patients with PA.

Adolescent↗
PubMed2003

Rib defects in patterns of multiple malformations: a retrospective review and phenotypic analysis of 47 cases.

Rib anomalies may occur in isolation, as well as in association with abnormalities of vertebral segmentation and multi-system malformations. Specific entities include the VACTERL and MURCS associations, spondylocostal dysostosis, and spondylothoracic dysostosis. The relative significance of rib anomalies in other lesser known syndromes and associations remains unclear. To document the diagnoses and related defects in patients with rib anomalies as part of broader pattern of anomalies, we retrospectively identified 47 cases from a hospital population, and evaluated specific costal findings and associated birth defects. In our study, fusion was the most common pattern of rib anomaly (72%), followed by bifid (28%) and hypoplastic ribs (26%). Unrecognized patterns of multiple congenital anomalies (MCA) and VACTERL association were the commonest specific diagnoses with a frequency of 30 and 28%, respectively. An associated vertebral defect was found in 72% of the patients. Of those with no vertebral anomaly, the combinations of "rib and cardiac defects alone" and "rib and renal defects alone" were seen in one-third of the patients (4/13). Both the occurrence and type of rib anomaly were helpful in defining certain syndromes and enhanced the likelihood of identifying related malformations.

Abnormalities, Multiple↗
PubMed2003

The floppy infant: contribution of genetic and metabolic disorders.

The floppy infant syndrome is a well-recognized entity for pediatricians and neonatologists. The condition refers to an infant with generalized hypotonia presenting at birth or in early life. The diagnostic work up in many instances is often complex, and requires multidisciplinary assessment. Advances in genetics and neurosciences have lead to recognition of newer diagnostic entities (several congenital myopathies), and rapid molecular diagnosis is now possible for several conditions such as spinal muscular atrophy (SMA), congenital muscular dystrophies (CMD), several forms of congenital myopathies and congenital myotonic dystrophy. The focus of the present review is to describe the advances in our understanding in the genetic, metabolic basis of neurological disorders, as well as the investigative work up of the floppy infant. An algorithm for the systematic evaluation of infants with hypotonia is suggested for the practicing pediatrician/neonatologist.

Diagnosis, Differential↗
PubMed2002

Smith-Lemli-Opitz syndrome: new mutation with a mild phenotype.

Smith-Lemli-Opitz syndrome (SLOS) (Online Mendelian Inheritance in Man, OMIM, 2001, http://www.ncbi.nlm.nih.gov/omim/ for SLOS, MIM 270400) is an autosomal recessive disorder of cholesterol biosynthesis caused by mutations of the 3beta-hydroxysterol Delta(7)-reductase gene, DHCR7. We report on a female infant with an exceptionally mild phenotype of SLOS, in whom molecular studies identified a new mutation in DHCR7. The proposita initially presented with feeding difficulties, failure to thrive, hypotonia, mild developmental delay, and oral tactile aversion. She had minor facial anomalies and 2-3 syndactyly of her toes in both feet. The plasma cholesterol was borderline low at 2.88 mmol/L (normal 2.97-4.40 mmol/L). Elevated plasma 7-dehydrocholesterol level of 200.0 micromol/L confirmed the clinical diagnosis of SLOS. Molecular analysis demonstrated compound heterozygosity for IVS8-1G -->C and Y280C, a new missense mutation in DHCR7. Since the other mutation in this patient is a known null mutation, this newly discovered mutation is presumably associated with significant residual enzyme activity and milder expression of clinical phenotype.

Cholesterol↗
PubMed2002

Genetics and cardiac anomalies: the heart of the matter.

The recent exponential increase in knowledge in genetics has revolutionized all aspects of medicine. The completion of the first draft of the human genome project has provided for clinicians a range and depth of information never before imagined. Over the last 25 years understanding the anatomical and physiological basis of a number of congenital cardiac anomalies has led to better care and outcome for the patients born with congenital cardiac defects. In the last decade the role of genes, their critical timing of expression, and understanding of important downstream pathways for optimizing normal development and control of the left right asymmetry have emerged. The progress in cardiac genetics has been supplemented by advances in cardiac imaging modalities leading to improvements in diagnosis of the cardiac anomalies. About 30% of all congenital heart diseases are associated with extra- cardiac malformations. Chromosomal anomalies are more common in patients with cardiac anomalies than the general population. Presence of facial dysmorphic features and associated extra-cardiac anomalies should alert the pediatricians to an underlying syndrome diagnosis. Newer molecular cytogenetics techniques such as fluorescence in situ hybridization (FISH) and molecular tests are now routinely utilized for confirming clinical diagnoses. In this review we have summarized clinical features and discussed the genetic basis of several syndromes (for example, 22q11 deletion syndrome, Williams syndrome, Down Syndrome, Kabuki syndrome etc.) where specific cardiac anomalies are frequently encountered. The importance of establishing an accurate clinical diagnosis cannot be over emphasized. The families need genetic counselling with accurate information on the recurrence risks. With the advent of the Internet and rapid access to information, the clinicians and the patient families can access valuable information regarding the prognosis, natural history, and clinical interventions for the affected child, and useful support groups for the family. Detection of cardiac anomalies during antenatal period warrants a genetics assessment.

Chromosome Deletion↗