Trisomy 18, esophageal atresia, anomalies of the radius, and congenital hypoplastic thrombocytopenia.

Abstract

Since the initial description of trisomy 17–18 as a clinical syndrome (1), a large number of reports have delineated a variety of its clinical and roentgen features (2–4). The combination of characteristic findings often permits diagnosis prior to chromosomal confirmation. We have recently observed three cases of trisomy 18 with unusual manifestations that warrant inclusion in the expanding clinical spectrum of this syndrome. These changes were esophageal atresia, malformations of the radius, and congenital thrombocytopenia. Radial anomalies were present in all three infants, esophageal atresia and thrombocytopenia in two. One child died within thirty hours after birth, and a chromosomal karyotype was not obtained. The clinical, roentgenological, and pathological findings, however, were characteristic of trisomy 18. Karyotype confirmation of trisomy 18 was obtained in the other two infants. CASE I: A 1600 g female was delivered by a 30-year-old mother following a forty-week gestation. Labor was induced because of polyhydramnios. At birth, the infant was in no distress. Multiple congenital anomalies, however, were apparent. The head was large, the chin receded, the mouth fish-like, and the ears low and posterior. There was marked flexion deformity of both wrists and incurving of the forearms. Only four fingers were present on the right hand. A harsh presystolic murmur was noted over the entire precordium. The infant regurgitated excessive amounts of mucus and, on the second day of life, roentgen examination revealed a distended proximal esophageal pouch with no air within the abdominal viscera (Fig. 1, A). Gastrografin was instilled, and the diagnosis of esophageal atresia without tracheoesophageal fistula was confirmed (Fig. 1, B). On the following day, an esophagostomy and gastrostomy were performed, with placement of a feeding tube. Roentgen study of the skeleton revealed a small narrow pelvis demonstrating the so-called antimongoloid configuration. The right arm (Fig. 1, C) exhibited hypoplasia of the radius and a curved ulna. Only four digits and four metacarpals were present. The first digit of the left hand (Fig. 1, D) was hypoplastic, and the second digit overlay the third. The middle and distal phalanges of the fifth digit were also hypoplastic. A V-shaped notch separated the fourth and fifth digits. An elongated skull was also noted, with a large posterior fossa and a small mandible. An intravenous urogram demonstrated a left-sided, crossed, fused ectopia with a double collecting system and double ureters draining the left kidney. The diagnosis of trisomy 18 was suggested, and chromosome configuration was obtained. The child did moderately well for approximately one month but gained little weight. During this time no hematological abnormalities were noted. At two months of age, she became dyspneic and cyanotic. X-ray examination of the chest showed a right upper lobe pneumonia and cardiac enlargement.