Twin brothers with MIDAS syndrome and XX karyotype.

Twin brothers with microphthalmia, facial dermal hypoplasia, sclerocornea, and supraventricular tachycardia, are reported. Their clinical features are compatible with MIDAS syndrome, a known X-linked and hemizygous male lethal condition. Their karyotypes showed an XX sex chromosome modality with a subtle Xp/Yp translocation proven by the presence of SRY gene. The pregnancy was complicated with fetal supraventricular tachycardia, which was treated with digoxin prenatally. Postnatally, both twins required treatment with adenosine, digoxin, and propanolol to remain in normal sinus rhythm. The possible involvement of the heart, only in the form of cardiomyopathy with arrhythmia is emphasized. Both twins had a selective X-inactivation of the derivative chromosome X with Xp/Yp translocation.

Neonatal alloimmune neutropenia in premature monozygous twins.

Alloimmune neonatal neutropenia (ANN) is an uncommon but potentially life-threatening disorder of the neonate and young infant. Hematologically, the mother's peripheral neutrophil count is normal. However, the passive transfer of maternal immunoglobulin G neutrophil-specific antibodies and the subsequent sensitization of fetal neutrophils can result in severe neutropenia in the neonate. Generally, ANN is a self-limiting condition, but with severe bacterial infection, mortality can be high. We present the clinical features of monozygous twins delivered at 33 weeks' postconception with this condition. This case report is unique in that it occurred in twins born prematurely and was attributable to antibodies against 2 neutrophil-specific antigens, NA1 and NB1. A brief review of the diagnosis, management, and treatment of ANN is presented.

Alloimmunization by hr'(c), hemolytic disease of newborns, and perinatal management.

A study was made of hr'(c) hemolytic disease to determine its natural history and to develop criteria for its management. Anti-c is 0.52 as frequent as anti-D(Rho) in gravid women. Seventy-four percent of infants born of c-alloimmunized women mated to c-positive men show serologic evidence of hemolytic disease of newborns. Up to 40% of affected infants require transfusion. There is evidence that ABO incompatibility between mother and fetus protects against alloimmunization. Although alloimmunization is frequently related to fetomaternal bleeding, severe hemolytic disease appears to be associated with previous maternal transfusion. Maternal antiglobulin titers of less than 1:16 are usually associated with mild disease or none at all. Women with higher titers, whose mates are hr'(c)-antigen positive, are candidates for amniotic fluid pigment analysis.

Kell alloimmunization, hemolytic disease of the newborn, and perinatal management.

The relative frequency of Kell (K:1) antibodies in pregnant women and a series of cases of Kell hemolytic disease of newborns were evaluated to review the strategy of managing potential disease. Among reproductive-aged women, Kell antibodies are about 60% as frequent as Rho (D) antibodies, but Kell disease is only 3% as common as Rho hemolytic disease. The reason is related to frequent transfusion-alloimmunization by Kell antigen and the low frequency of the K:1 gene among fathers. Kell hemolysis is severe in about half of cases. Amniocentesis is indicated in only a few circumstances: previous child with erythroblastosis fetalis, significant increase in maternal Coombs titer, presence of Kell antigen in the father, and after comparison of the relative risks of hemolytic disease and amniocentesis in each patient. Screening for Kell antigen before transfusing premenopausal women would be a means of avoiding erythroblastosis, but the rarity of severe disease does not justify this approach.

Maturation of the brain-stem auditory evoked potential in premature infants.

Patterns of development and extent of variability of the brain-stem auditory evoked potential (BAEP) are described in 52 healthy premature infants and 50 normal term newborns with reliable conceptional ages. Binaural and monaural stimulation are compared. Serial studies of individual prematures are emphasized and demonstrate that the most consistent and least variable measures are the monaurally derived interpeak intervals. All the BAEP parameters studied mature including wave form, relative amplitude, peak and interpeak intervals, but there is far more variability in preterms than in term infants or adults, even when infants are carefully matched for conceptional age. As term is approached, BAEP variability decreases substantially, suggesting that near term the BAEP becomes a more reliable indicator of neurologic function. The variability of the BAEP in the normal preterm limits its usefulness in determining neurologic dysfunction in individual high risk infants. Nevertheless, the BAEP may still prove useful for defining group differences among infants and could provide an objective measure of those factors influencing neurologic development. Serial change in the BAEP is a specific parameter which we believe merits further study in premature infants as an index of neurologic maturation.

Hearing screening of high-risk newborns with brainstem auditory evoked potentials: a follow-up study.

Numerous techniques have been used in attempts to find a reliable and efficient screening method for determining auditory function in the newborn. The brainstem auditory evoked potential (BAEP) is the latest method advocated for that purpose. The BAEP was evaluated as a hearing screening test in 168 high-risk newborns between 35 and 45 weeks of conceptual age. Follow-up data were obtained after 1 year (mean 17.3 months) on 134 of the infants (80%). Normal hearing was defined as a reproducible response in both ears to a 25 dB normal hearing level (nHL) click stimulus; 21 infants (12.5%) failed the initial screening test. Follow-up on 19/21 infants revealed 18 infants with normal hearing and one infant with an 80 dB nHL bilateral hearing loss substantiated. One infant with an abnormal screening test died before retesting, and the other infant was lost to follow-up but had only a unilaterally abnormal BAEP. None of the infants with a normal BAEP screening study had evidence of hearing loss on retesting. Sensitivity of the BAEP was 100%, specificity was 86%, predictive value of a positive test was 5.26%, and the predictive value of a negative test was 100%. The incidence of significant hearing loss in our population was between 0.75% (1/134 infants) confirmed, and 2.24% (3/134 infants) including infants who failed screening but were lost to follow-up. The BAEP is a sensitive procedure for the early identification of hearing-impaired newborns. However, the yield of significant hearing abnormalities was less than predicted in other studies using BAEP for newborn hearing screening.

Isolated hypoglossal nerve paralysis following influenza vaccination.

Isolated right hypoglossal (12th) nerve paralysis occurred after bivalent killed influenza vaccine (types A and B) immunization of a 7-month-old girl with cystic fibrosis. Two days after the third immunizing dose, fever and right hypoglossal paralysis developed. There were no other neurologic signs, and she recovered completely over the following three months.

Experimental transmission of Enterobacteriaceae by insects. I. Fate of Salmonella fed to the hide beetle Dermestes maculatus and a novel method for mounting insects.

A method of mounting insects was devised. The procedure is simple to perform and facilitates quantitative bacteriological studies of feces with a minimal possibility of cross contamination. By this method, it was observed that approximately 10(7) cells of Salmonella were required for passage through the intestinal tract. Multiple doses of this magnitude were necessary to initiate intestinal infection. The numerical considerations cast doubt that Dermestes is involved significantly in the dissemination of Salmonella in the environment of food and feed plants.