Genética de la sordera congénita / Genetics of congenital deafness

Congenital deafness is defined as the hearing loss which is present at birth and, consequently, before speech development. It is the most prevalent sensor neural disorder in developed countries, and its incidence is estimated between 1-3 children per 1,000 newborns, of which more than 50% are attributable to genetics causes. Deafness can be classified as syndromic or non-syndromic. In the first case, it is associated with outer ear malformations and/or systemic findings. More than 400 syndromes accompanied of deafness have been described, which represent about 30% of cases of congenital hearing loss. The remaining percentage corresponds to non-syndromic cases: 75-85% are autosomal recessive, 15-24% are autosomal dominant, and 1-2% are X-linked. The evaluation of a child with deafness requires a multidisciplinary collaboration among specialists, who must coordinate themselves and give information to the affected family. The aims of establishing a diagnosis are to predict other manifestations that may suggest some syndrome and to anticipate their management, as well as to perform genetic counseling to parents and affected individuals (AU)

La sordera congénita se define como la pérdida auditiva que se presenta en el momento del nacimiento y, por lo tanto, antes del desarrollo del habla. Es el trastorno sensorioneural más prevalente en países desarrollados, con una incidencia de 1-3 niños por cada 1.000 recién nacidos vivos, de los cuales más del 50% son atribuibles a causas genéticas. La sordera se puede clasificar como sindrómica o no sindrómica. En el primer caso, está asociada con malformaciones del oído externo y/o alteraciones en otros órganos y sistemas. Se han descrito más de 400 síndromes que presentan déficit auditivo, que dan cuenta del 30% de los casos genéticos. El 70% restante corresponde a casos no sindrómicos, dentro de los cuales el 75-85% son de herencia autosómica recesiva, el 15-24% autosómica dominante y el 1-2% ligada al cromosoma X. La evaluación de un niño con sordera requiere de la participación de diversos especialistas, quienes deben coordinarse y entregar la información a la familia. Los objetivos de establecer un diagnóstico son predecir otros hallazgos clínicos que sugieran algún síndrome y anticiparse en su tratamiento y proveer consejo genético a los padres e individuos afectados (AU)

[Genetics of congenital deafness]. / Genética de la sordera congénita.

Congenital deafness is defined as the hearing loss which is present at birth and, consequently, before speech development. It is the most prevalent sensor neural disorder in developed countries, and its incidence is estimated between 1-3 children per 1,000 newborns, of which more than 50% are attributable to genetics causes. Deafness can be classified as syndromic or non-syndromic. In the first case, it is associated with outer ear malformations and/or systemic findings. More than 400 syndromes accompanied of deafness have been described, which represent about 30% of cases of congenital hearing loss. The remaining percentage corresponds to non-syndromic cases: 75-85% are autosomal recessive, 15-24% are autosomal dominant, and 1-2% are X-linked. The evaluation of a child with deafness requires a multidisciplinary collaboration among specialists, who must coordinate themselves and give information to the affected family. The aims of establishing a diagnosis are to predict other manifestations that may suggest some syndrome and to anticipate their management, as well as to perform genetic counseling to parents and affected individuals.

[Prevalence of congenital malformations and low weight at birth among teenage mothers]. / Prevalencia al nacimiento de malformaciones congénitas y de menor peso de nacimiento en hijos de madres adolescentes.

BACKGROUND: In Chile, 14 to 16% of births occur in teenage mothers. These mothers apparently have a higher frequency of premature labor, low birth weight and congenital malformations. AIM: To assess the frequency of prematurity, congenital malformations and weight at birth among the offspring of adolescent mothers. PATIENTS AND METHODS: The births occurred in a hospital between 1982 and 2001, were analyzed using the Latin American Collaborative Study for Congenital Malformations (ECLAMC) data base. Mothers were classified as teenagers when their age ranged between 10 and 19 years old and older when their age was over 20 years old. All women were subdivided as cases and controls. RESULTS: The sample was formed by 894 teenage and 806 older mothers. Seven percent of both teenage and older mothers had offspring with one or more malformations. The incidence of low birth weight newborns and of prematurity was also similar in both groups of mothers. CONCLUSIONS: In this sample, offspring of teenage mothers do not have a higher frequency of malformations, low birth weight or prematurity.

[Fetal ovarian cyst: prenatal echographic diagnosis. Evolution and postnatal treatment. Clinical cases]. / Quiste ovárico fetal: diagnóstico ecográfico prenatal. Evolución y tratamiento postnatal. Casos clínicos.

Ovarian cysts are found in 32% of necropsies performed to neonates. They can also be diagnosed during gestation by ultrasonography. The clinical evolution of these cysts is variable, but in most cases the prognosis is favorable. Some complications such as ovarian torsion, bleeding, rupture and peritonitis have been described. We report two newborn girls with ovarian cysts, diagnosed during gestation. One required an emergency operation due to vomiting and abdominal distension, interpreted as a possible torsion of the cyst. The second girl was operated at the fourth day of life, finding a left ovarian cyst with torsion of the pedicle. Both girls had a favorable postoperative evolution.