RESUMO
OBJECTIVE: Prolonged neonatal jaundice, beyond day 14 of life, is very common and of concern to the clinician. The aim of this study was to investigate whether a genetic mutation in the bilirubin UGT1A1 gene, which has been associated with Gilbert's syndrome in adults, is a contributory factor in prolonged neonatal jaundice. STUDY DESIGN: Blood was collected from 85 term newborns with unexplained hyperbilirubinemia, and DNA was prepared. The neonates were divided into 6 groups depending on whether they were breast-fed or bottle-fed and whether they had acute, prolonged, or very prolonged jaundice. UGT1A1 TATA promoter genotyping (DNA test for Gilbert's syndrome) was performed on all samples, and analysis of the entire UGT1A1 coding sequence was performed in a representative sample (11 of 26) of very prolonged cases. RESULTS: In addition to the known common UGT1A1 TATA alleles (TA6 and TA7), a novel TATA allele (TA5) in a neonate with very prolonged jaundice was identified. Statistical analysis of the TATA genotype distributions within the group of breast-fed neonates revealed significant differences among the acute, prolonged, and very prolonged subgroups (.05 > P >.01): the incidence of familial hyperbilirubinemia genotypes (7/7 and 5/7) is 5 times greater in very prolonged cases (31%) relative to acute cases (6%). Neonates with prolonged jaundice from family pedigrees were observed to demonstrate the Gilbert's phenotype as children or young adults. CONCLUSIONS: A genetic predisposition to develop prolonged neonatal hyperbilirubinemia in breast-fed infants is associated with TATA box polymorphism of the UGT1A1 gene and will be recognized as Gilbert's syndrome in adulthood.
Assuntos
Aleitamento Materno/efeitos adversos , Doença de Gilbert/genética , Glucuronosiltransferase/genética , Hiperbilirrubinemia Hereditária/genética , Adolescente , Adulto , Alimentação com Mamadeira , Criança , Feminino , Genótipo , Doença de Gilbert/complicações , Humanos , Hiperbilirrubinemia Hereditária/etiologia , Recém-Nascido , Masculino , Linhagem , Reação em Cadeia da Polimerase , Polimorfismo Genético , Análise de Sequência , TATA Box/genéticaRESUMO
In a series of 79 consecutive preterm infants who were ready for discharge, 14 (18%) infants were unable to maintain normal concentrations of blood glucose. This finding suggests that a significant number of preterm infants are at risk of hypoglycemia at home if a feed is omitted or delayed.
Assuntos
Glicemia/metabolismo , Glucose-6-Fosfatase/sangue , Hipoglicemia/etiologia , Recém-Nascido Prematuro/sangue , Peso ao Nascer , Glicemia/análise , Feminino , Privação de Alimentos/fisiologia , Idade Gestacional , Humanos , Hipoglicemia/classificação , Hipoglicemia/diagnóstico , Recém-Nascido , Lactatos/sangue , Masculino , Alta do Paciente , Fatores de Risco , Índice de Gravidade de DoençaRESUMO
This study tests the hypothesis that increasing the calcium and phosphorus content of formulas for very low birth weight (VLBW) infants to the level required to decrease the incidence of rickets has a negative impact on magnesium balance. Using formulas variously supplemented with these minerals, we measured absorption and retention in two groups of preterm infants: (1) VLBW infants, less than 1500 gm and at less than 32 weeks of gestational age, with 3-day mineral balances begun at days 10, 20, 30, and 40; and (2) low birth weight infants appropriately grown and at 32 to 34 weeks of gestational age, with a single 3-day balance begun at day 10. Magnesium did not affect calcium balance in VLBW or low birth weight infants but promoted phosphorus retention in VLBW infants from day 20 onward. Absorption and retention of magnesium increased with postnatal age in VLBW infants, but this effect was obvious only when calcium or phosphorus intakes were low or when magnesium intake was high. Calcium and phosphorus supplementation further reduced magnesium absorption and retention in VLBW infants to the extent that they were in negative balance throughout the study; however, magnesium supplementation improved absorption and retention in VLBW infants. The low birth weight infants absorbed and retained more magnesium than VLBW infants at the same postnatal age whether or not magnesium was supplemented. We conclude that magnesium deficits occur at currently recommended intakes of 10 mg/kg/day for VLBW infants with calcium and phosphorus intakes that allow retentions equivalent to in utero accretions; however, with magnesium intakes approaching 20 mg/kg/day, appropriate retention can be achieved.
Assuntos
Envelhecimento/metabolismo , Cálcio/farmacologia , Idade Gestacional , Recém-Nascido de Baixo Peso/metabolismo , Magnésio/metabolismo , Fósforo/farmacologia , Absorção , Animais , Cálcio/administração & dosagem , Cálcio/sangue , Estudos de Coortes , Nutrição Enteral , Humanos , Alimentos Infantis , Recém-Nascido , Magnésio/administração & dosagem , Magnésio/sangue , Magnésio/farmacologia , Magnésio/urina , Masculino , Leite , Fósforo/administração & dosagem , Fósforo/sangueRESUMO
Forty-six infant boys less than 1500 g at birth and less than 32 weeks gestation were fed enterally from birth until day 47. Cohorts were given milk formula varying in calcium and phosphorus content: group A, calcium 45 mg/dL, phosphorus 33 mg/dL; group B, calcium 85 mg/dL, phosphorus 33 mg/dL; group C, calcium 125 mg/dL, phosphorus 33 mg/dL; group D, calcium 125 mg/dL, phosphorus 50 mg/dL; and group E, calcium 125 mg/dL, phosphorus 64 mg/dL. Three-day balance studies were begun at days 10, 20, 30, and 40. Calcium net absorption and retention were influenced by postnatal age and calcium intake. Calcium retention best approached intrauterine accretion rates in group C. Phosphorus was well absorbed irrespective of the calcium content of the milk. Phosphorus retention increased with increments in the calcium content of the milk. Increasing the phosphorus content of the milk (groups D and E) resulted in no overall change in calcium absorption and retention but some increments in phosphorus retention.
Assuntos
Cálcio/metabolismo , Recém-Nascido Prematuro , Fósforo/metabolismo , Peso ao Nascer , Cálcio/sangue , Cálcio/urina , Nutrição Enteral , Fezes/análise , Idade Gestacional , Humanos , Alimentos Infantis/análise , Recém-Nascido , Masculino , Fósforo/sangue , Fósforo/urina , Estatística como AssuntoRESUMO
Seventy-four infants weighing less than 1500 gm at birth were fed enterally from birth until day 47. Group A (18 infants) were given SMA Gold Cap: group B (18 infants), supplementary calcium to 21 mmol/L (84 mg/dl); group C (16 infants), further calcium supplementation to 31.2 mmol/L (125 mg/dl); and group D (22 infants), milk with calcium content 31.2 mmol/L (125 mg/dl) and phosphorus supplementation to 15.7 mmol/L (49 mg/dl). The addition of calcium reduced the radiologic evidence of rickets, and combined calcium and phosphorus supplementation maintained plasma alkaline phosphatase activity within the normal range for 6 weeks.