Marta olombo C

Fenilquetonuria de diagnóstico neonatal y lactancia materna

9.5 mg Phe/kg/day. Fifteen children maintained theblood level of Phe under 8 mg/dl, considered an excellent metabolic control. Only 4 cases hadintermittently high levels, between 10-12 mg/dl. At 6 months of age, 74% of the children main-tained breast feeding as the only source of Phe. Sixty three percent had a normal nutritionalstatus, 5.2% were at nutritional risk and 31.6% were overweight. Eighty one percent had a nor-mal mental development.

Diagnóstico y seguimiento de 23 niños con acidurias orgánicas

Background: Propionic aciduria (PA) and Methymalonic aciduria (MMA) result from an inherited abnormality of the enzymes propionyl CoA carboxylase and methylmalonyl CoA mutase respectively. This produces marked increases in the amino acids methionine, threonine, valine and isoleucine (MTVI). Their clinical presentation can be neonatal or late onset forms. Aim: To report 23 children with organic acidurias. Material and methods: Twenty three cases of organic acidurias diagnosed since 1980 (17 PA and 6 MMA) and followed at the Institute of Nutrition and Food Technology, are reported. Results: The average age of diagnosis was 3.9 days for the neonatal form and 8.3 months for the late onset form. The most frequent symptoms were hypotonia, lethargy and vomiting. Neonatal PA had mean ammonemias of 1089±678.3 µg/dl. The figure for MMA was 933±801.9 µg/dl. Seven children were dialyzed and 30% died. 16 children are followed and 81.2% have normal weight for age. Seven children required gastrostomy because of anorexia and failure to thrive. The nutritional treatment is based on natural and artificial proteins without MTVI, with periodical controls, amino acid and ammonia quantification. Some patients were submitted to enzyme assays and molecular studies. Conclusions: An early diagnosis and a very strict follow up allows a normal development of children with organic aciduras. There is a relationship between prognosis and the presentation form, the nutritional status and the emergency treatment during acute episodes. The importance of the enzymatic and molecular studies is emphasized because they facilitate treatment, accurate diagnosis and allow an adequate genetic counseling (Rev Med Chile 2002; 130: 259-66)

Diagnóstico de fenilquetonuria en Chile

The clinical and biochemical characteristics of 44 PKU children, diagnosed at an average age of 3 years 11months is presented. 90% of these children consulted because of delayed psychomotor development or mentalretardation: 100% of them showed hypopigmented skin, but only 32% had bright colored eyes, 86% had a peculiarmust odor. The neurological signs and symptoms were predominantly hyperactivity, irritability, hypotonia andhyperreflexia. Fenic chloride and 2-4 dinitrophenylhydrazine tests were positive in all patients. Paper chromato-graphy of amino acids demonstrated levels of phenylalanine over 20 mg%. The importance of making an earlydiagnosis and treatment in order to prevent mental retardation is emphasized. The need to develop newborn screen-ing for PKU in our country is raised.(Key words: phenylketomiria, PKU.)

Síndrome de deficiencia del transportador de glucosa tipo 1 (SDGLUT-1) tratado con dieta cetogénica: Caso clínico

The glucose transporter type 1 deficiency syndrome (GLUT-1 SD)(OMIM 606777) is an inborn error of metabolism of brain glucose transport. The characteristicclinical manifestations are seizures, hypotonia, developmental delay, microcephaly andhypoglycorrhachia. We report a girl with normal weight and height at birth. At 6 weeks of ageshe started with convulsions reaching up to 20 myoclonic seizures a day. She was treated withvalproate, phenobarbital and carbamazepine without response. Blood analysis includingaminoacids and acylcarnitines were all normal. The brain MRI showed frontal atrophy with anincreased subarachnoidal space and Electroencephalography was abnormal. Blood glucose was84 mg/dl and spinal fluid glucose 26 mg/dl with a ratio of 0.31 (Normal Ratio >0.65

Pesquisa etiológica en espasmos masivos

A systematic clinical protocol was applied in 16 infants that suffered from infantile spasms (IS) in order to identify etiologic factors. A positive family history was present in 2/16 patients and relevant perinatal or postnatal pathology in 5/16. Psychomotor retardation and other seizures anteceded IS in 10/16 and 8/16 infants respectively. Physical and neurologic examination revealed microcephalia (4/16), dysmorphic features (2/16), hypopigmented skin lesions (1/16) and pyramidal syndrome (8/16). Neuroimaging technics yielded positive findings in 9/16 patients, diffuse or localized atrophy (7/16), porencephalic cysts (3/16), periventricular calcifications (1/16), callosal agenesis (1/16). Laboratory examination allowed diagnosis of two metabolic diseases: congenital hyperlactatemia an maple syrup urine disease. Two patients were classified as cryptogenetic and fourteen as symptomatic. Within the latter an etiologic factor was identified in 12/14. This study underlines the value of etiologic search in IS, because it may contribute substantially to specific treatment and genetic counselling.

Programa de rastreo neonatal de Fenilquetonuria

A screening program for phenylketonuria in newborn infants that is being carried out at one of the Metropolitan Health Services at Santiago, Chile for the last 17 months, using the Guthrie test, is described. During this period 15,214 blood samples have been analyzed, which represented 94.4% coverage for beneficiary newborn infants. Two cases of transient hyperphenylalaninemia, one patient with benign hyperphenylalaninemia, and one infant with classical phenylketonuria have been thus identified. In this last child nutritional management was started at 13 days of life. Screening programs for early detection of phenylketonuria in Chile seem convenient, feasible and reliable.

Enfermedad de Tay Sachs

La enfermedad de Tay-Sachs es causada por un gen defectuoso en el cromosoma [2] 15. Cuando ambos padres portan el gen defectuoso para esta enfermedad, el hijo tiene un 25% de probabilidades de desarrollarla. El nino tiene que recibir dos copias del gen defectuoso, una de cada uno de los padres, para resultar enfermo. Si solo uno de los padres le transmite dicho gen defectuoso, el nino se denomina portador y no se enfermara, pero tendra el potencial de transmitirle la enfermedad a sus hijos.

Síndrome de hiperamonemia congénita

El amonio, siendo toxico para el sistema nervioso, se mantiene en niveles hematicos muy estables gracias al equilibrio existente entre su absorcion exogena mas su produccion endogena, menos su utilization o eliminacion (Fig1)Gran parte del amonio, tanto el ingerido como el metabolizado por el organismo se fija como urea, es por esto que cualquier bloqueo metabolico del ciclo de la urea produce hiperamonemia y a modo de compensacion, las otras vias de metabolizacion adquieren mayor importancia (cerebro-ririon)

Detección de portadores sanos en la distrofia muscular progresiva 24 familias

La Distrofia Muscular Progresiva Pseudohipertrdfica tipo Duchenne (DMP), es la mas frecuente de las Distrofias Musculares (1). Se distingue de ellas, por tener herencia recesiva ligada al sexo, por comenzar en la epoca preescolar, por tener una rapida progresi6n de los sintomas hasta un desenlace fatal y por el aumento de volumen de los musculos de las pantorrillas (2) (3). De acuerdo a recientes clasificaciones se han descrito dentro de este cuadro, por lo menos otras dos formas: el tipo menos severo, tambien ligado al sexo, de comienzo tardio y larga sobrevida, llamado de Becker y una forma igual al tipo Pseudohipertrofico, pero que muestra una fuerte tendencia a ser heredado de manera autosomka recesiva (2) y ser mas lentamente progresivo (3). La frecuencia de la enfermedad no ha sido definitivamente estudiada pero las estimaciones efectuadas, revelan una prevalencia de 66 enfermos vivos por 1 millon de hombres vivos y una incidencia de 279 pacientes por 1 millon de recien nacidos varones (4). Aplicando este criterio para nuestro pais deberiamos obtener una prevalencia de 330 casos y una incidencia de 35 enfermos por afio (5). Es sabido que el tratamiento es solo paliativo, de aqui que la orientation gen6tica de los familiares es por el momento la unica alternativa para disminuir la incidencia del cuadro mediante el consejo gengtico. Numerosas investigaciones han sido emprendidas con el fin de determinar por medio de diversas tecnicas a los portadores: electromiografia, biopsia muscular, isoenzimas de la dehidrogenasa lactica muscular, creatinina, inmunoelectroforesis del suero, electrocardiograma, transaminasas, al-