Microgastria in the Genetic Clinic

Abstract

Microgastria is a rare developmental anomaly of the gastrointestinal tract that occurs during organogenesis(5^th to 9^th week of gestation). It could be a solitary malformation or part of multiple anomalies(syndromic microgastria). Prenatally absent/tiny stomach bubble is the sonographic sign. Between January 2, 1982 and April 15, 1999 through the University of South Florida Genetic clinics there were ten probands with suspected/confirmed microgastria. They were part of the 35414 probands/families evaluated. Four were seen through the pediatric genetic clinic. All had microgastria with associated anomalies: JC a Mexican one-year-old boy had it with extensive partial albinism, mixed bilateral hearing loss, blepharophimosis, abnormal nasolacrimal ducts. ASD, pulmonic stenosis, pectus carinarum, asymmetric brachydactyly, mild mental retardation and 46, XY karyotype. JH was a newborn Caucasian girl with polyhydramnios, intrauterine growth retardation, TE fistula, tetralogy of Fallot, partial situs-inversus. second and third toe syndactyly and 46, XX karyotype. CC was a premature newborn Caucasian girl with polyhydramnios. TE fistula, spleen with extraneous lobe, GE reflux that required Nissen fundoplicalion, pectus carinatum and left inguinal hernia. DW was a newborn Caucasian boy with left cleft lip and palate. GE reflux, ectrodactyly including lobster foot, failure to thrive, short stature and 46, XY karyotype. All required frequent small feedings and DW had surgery to create a larger stomach.

PS, LM, MM. RC, SS and CS were seen through the prenatal clinic/fetal board registry. On targeted sonograms their fetuses did not show a “stomach bubble”. The male fetus of PS had Trisomy 21 with single umbilical artery and polyhydramnios; a stillbirth took place(PS developed class A1 diabetes mellirus during the gestation). LM had a stillborn girl with anencephaly, sacral spina bifida and cleft lip. Autopsies of the stillborns were declined. The 46, XX fetus of MM showed also single umbilical artery and polyhydramnios. The fetuses of RC, SS and CS did not show other abnormalities but all failed to return to the clinic.

Comparing these pediatric/genetic and prenatal patients it is obvious that postnatal genetic evaluations are a must whenever microgastria is suspected. Without them “no stomach bubble” may or may not represent microgastria. The same applies to the stillboms withoutautopsies. The “absent bubble” is a sonographic impression which requires confirmation. Otherwise overdiagnosis of microgastria is taking place.