Recombinant human acid [alpha]-glucosidase: major clinical benefits in infantile-onset Pompe disease.

BACKGROUND: Pompe disease is a progressive metabolic neuromuscular disorder resulting from deficiency of lysosomal acid alpha-glucosidase (GAA). Infantile-onset Pompe disease is characterized by cardiomyopathy, respiratory and skeletal muscle weakness, and early death. The safety and efficacy of recombinant human (rh) GAA were evaluated in 18 patients with rapidly progressing infantile-onset Pompe disease. METHODS: Patients were diagnosed at 6 months of age and younger and exhibited severe GAA deficiency and cardiomyopathy. Patients received IV infusions of rhGAA at 20 mg/kg (n = 9) or 40 mg/kg (n = 9) every other week. Analyses were performed 52 weeks after the last patient was randomized to treatment. RESULTS: All patients (100%) survived to 18 months of age. A Cox proportional hazards analysis demonstrated that treatment reduced the risk of death by 99%, reduced the risk of death or invasive ventilation by 92%, and reduced the risk of death or any type of ventilation by 88%, as compared to an untreated historical control group. There was no clear advantage of the 40-mg/kg dose with regard to efficacy. Eleven of the 18 patients experienced 164 infusion-associated reactions; all were mild or moderate in intensity. CONCLUSIONS: Recombinant human acid alpha-glucosidase is safe and effective for treatment of infantile-onset Pompe disease. Eleven patients experienced adverse events related to treatment, but none discontinued. The young age at which these patients initiated therapy may have contributed to their improved response compared to previous trials with recombinant human acid alpha-glucosidase in which patients were older.

Antenatal corticosteroids and newborn screening for congenital adrenal hyperplasia.

OBJECTIVE: To assess the effect of reported corticosteroid exposure on neonatal levels of 17-hydroxyprogesterone (17-OHP), the cortisol precursor used in newborn screening for congenital adrenal hyperplasia, in newborns weighing less than 2500 g at birth. DESIGN: A retrospective study of newborns weighing less than 2500 g at birth and exposed to corticosteroids as reported on their newborn screening card compared with newborns weighing less than 2500 g at birth and reported as not exposed to corticosteroids. METHODS: Birth weight, gestational age, age at screening, special care information, and name of screening hospital were obtained from newborn screening cards for 16 115 newborns screened in Michigan during the first 3 months of 2000. Levels of 17-OHP, measured by fluoroimmunoassay, were obtained from Michigan's Newborn Screening Program database. RESULTS: The mean 17-OHP level for the 69 low-birth-weight newborns in the corticosteroid-exposed group was 52 ng/mL, which was higher than that for the 771 low-birth-weight newborns in the unexposed group (35 ng/mL) (P<.001). Reported corticosteroid use did not decrease the number of expected borderline positive screening results for congenital adrenal hyperplasia (P>.05). Levels of 17-OHP varied by birth weight in corticosteroid-exposed and unexposed newborns. CONCLUSIONS: Corticosteroid exposure may not suppress screening 17-OHP levels. Therefore, newborn screening should not be delayed in premature newborns because of antenatal exposure to corticosteroids.

Case of complex craniofacial anomalies, bilateral nasal proboscides, palatal pituitary, upper limbs reduction, and amnion rupture sequence: disorganization phenotype?

We report a case of a dizygotic twin with complex abnormalities of head, body, and limbs. The anomalies include the following: lateral and midline cleft upper lip, ectopic palatal pituitary, natal teeth, bilateral nasal proboscides with an absent nose, left microphthalmia with conjunctival-lined cyst, right ocular dysgenesis, bilateral retinal dysplasia, platybasia with skull asymmetry, hydrocephalus secondary to aqueductal atresia, brain hemispheric asymmetry with a parietal-occipital cortical flap, agenesis of posterior corpus callosum, absence of the olfactory nerves and left anterior cerebral artery, leptomeningeal and intraventricular heterotopias, right radial longitudinal terminal meromelia with constriction rings of fingers, partial syndactyly of the third and fourth left fingers, dorsiflexed great toes and pes equinovarus bilaterally, and multiple skin tags with a sacral appendage. Additionally, this twin's placental disc and extraplacental membranes were devoid of amnion. We regard these anomalies as a possible expression of the human homologue of the disorganization phenotype or another gene mutation. Nevertheless, an abnormality of blastogenesis with early damage to organizing tissues of the frontonasal region and limbs, or a vascular disruption, cannot be excluded. Early amnion rupture sequence (possible extraamniotic pregnancy with amniotic bands, limb reduction defects with Streeter bands, and multiple skin tags tapering into amniotic bands) was also present in this case, and may have acted as a contributing factor.

An investigation into the effects of inhibitors of fluid production by Locusta Malpighian tubule Type I cells on their secretion and elemental composition.

The intracellular elemental concentrations of K, Na, Cl, P, Mg and Ca within Type I cells of the Malpighian tubules of Locusta migratoria have been measured using electron probe X-ray microanalysis. The distribution of Na, K and Cl was not homogeneous within the cells and concentration gradients exist from basal to apical surfaces. The rate of secretion and the cationic composition of the secreted tubule fluid have also been determined. Furosemide (1 mM) inhibited fluid secretion by about 60%, raised the [Na(+)] but did not significantly alter the [K(+)] of the secreted tubule fluid. When Rb(+) replaced K(+) in the saline fluid secretion was also inhibited by about 60%, but no additional inhibition occurred by the simultaneous inclusion of furosemide. Thus, Rb(+) and furosemide probably act at the same transport site, and Rb(+) cannot substitute for K(+) at the basal membrane cotransporter. Bafilomycin (1 µM) dramatically inhibited fluid production by 85%, the [K(+)] of the secreted fluid was reduced by about 30% but the [Na(+)] was almost doubled. Furosemide, in common with other inhibitors of fluid secretion acting at the basal surface (ouabain and Rb(+)), caused a fall in intracellular [K] and a rise in [Na]. Bafilomycin, in common with N-ethyl maleimide, which acts at the apical surface, increased the intracellular [K] but did not affect the [Na].

Increased need for medical interventions in infants with velocardiofacial (deletion 22q11) syndrome.

Ten of 12 patients diagnosed with deletion 22q11.2 in infancy required a total of 26 hospitalizations during their first year of life. After heart disease, feeding and respiratory problems were the most frequent reasons for intervention.

Prader Willi and Angelman syndromes: exemplars of genomic imprinting.

The molecular phenomenon genomic imprinting provides an explanation for why two clinically distinct syndromes share genetic etiologies. Increased understanding of genomic imprinting is affecting diagnostics. Use of improved diagnostic tests can enable early, syndrome-specific, and anticipatory interventions and consequently, improved quality of life; however, these tests are of little use unless clinicians are able to identify at-risk patients. Nurses knowledgeable about Prader Willi and Angelman syndromes and their associated genetic mechanisms can play a significant role in early identification, referral, and intervention of patients with these conditions.

Progressive laryngotracheal stenosis with short stature and arthropathy.

Laryngotracheal stenosis is rare in adults, especially in the absence of a malignancy. It is most commonly caused by fibrosis following endotracheal intubation or tracheal trauma. Other conditions causing progressive airway narrowing include the mucopolysaccharidoses and autoimmune disorders. With the exception of storage diseases, there are no well-defined genetic disorders with progressive airway narrowing as a common complication. We have evaluated three unrelated individuals with this potentially life-threatening finding, all of whom have a previously unrecognized condition. Each patient had short stature and joint stiffness with no evidence for infectious, inflammatory, or metabolic diseases as a cause of their condition. None of our patients had clinical findings indicative of known skeletal dysplasias or storage diseases. They had minor facial anomalies which included deeply set eyes, bushy eyebrows, and flat midface. Given the unique findings of our patients including adult onset critical tracheal stenosis, short stature, progressive joint limitation, and distinct facial anomalies, we conclude that they have a previously undescribed condition.

A submicroscopic deletion in Xq26 associated with familial situs ambiguus.

Abnormal left-right-axis formation results in heterotaxy, a multiple-malformation syndrome often characterized by severe heart defects, splenic abnormalities, and gastrointestinal malrotation. Previously we had studied a large family in which a gene for heterotaxy, HTX1, was mapped to a 19-cM region in Xq24-q27.1. Further analysis of this family has revealed two recombinations that place HTX1 between DXS300 and DXS1062, an interval spanning approximately 1.3 Mb in Xq26.2. In order to provide independent confirmation of HTX1 localization, a PCR-based search for submicroscopic deletions in this region was performed in unrelated males with sporadic or familial heterotaxy. A cluster of sequence-tagged sites failed to amplify in an individual who also had a deceased, affected brother. FISH identified the mother as a carrier of the deletion, which arose as a new mutation from the maternal grandfather. The deletion interval spans 600-1,100 kb and lies wholly within the 1.3-Mb region identified by recombination. Discovery of this deletion supports localization of HTX1 to Xq26.2 and reveals the first molecular-genetic abnormality associated with human left-right-asymmetry defects.

New insights into the phenotypes of 6q deletions.

Deletions of chromosome 6q are rare. We report 3 new patients with 6q deletions. Case 1 is a male with an interstitial deletion [del(6)(q13q14.2)], hypotonia, speech delays, and minor anomalies. Case 2 is a male with an interstitial deletion [del(6)(q16.2q22.32)] and malformations, including truncus arteriosus and bilateral oligodactyly. Case 3 is a male with a terminal deletion [del(6)(q25.2)] with retinal pits, hydrocephalus, atrioventricular canal, and hydronephrosis. The findings in our patients and those from 57 previously reported cases demonstrated 3 phenotypic groups associated with 6q deletions. Group A [del(6)(q11-q16)] had a high incidence of hernias, upslanting palpebral fissures, and thin lips with lower frequency of microcephaly, micrognathia, and heart malformations. Group B [del(6)(q15-q25)] was associated with increased intrauterine growth retardation, abnormal respiration, hypertelorism, and upper limb malformations. Group C [del(6)(q25-qter)] was associated with retinal abnormalities, cleft palate, and genital hypoplasia. The only universal finding among all patients with 6q deletions was mental retardation. Other findings common to all 3 groups included ear anomalies (90%), hypotonia (82%), and postnatal growth retardation (68%).

Primary amoebic meningoencephalitis with Naegleria fowleri: clinical review.

Two children with primary amoebic meningoencephalitis secondary to Naegleria fowleri are reported. Both children died, and the causative agent was identified at autopsy. Presentation and outcome conformed to the usual course of primary amoebic meningoencephalitis and reaffirm the gravity and rapid progression of this infection. The epidemiology, microbiology, diagnostic considerations, and treatment are discussed. Primary amoebic meningoencephalitis should be considered in the differential diagnosis of children with meningitis or encephalitis.

The inconspicuous penis.

OBJECTIVE: To describe the etiology and management of the group of abnormalities referred to as the inconspicuous penis. DESIGN: Analysis of 19 cases seen over a period of 2 years by chart review. SETTING: Children's hospital in a major metropolitan area. PATIENTS: Nineteen boys referred to two pediatric urologists over a period of 2 years with penises that appeared abnormally small, but on palpation and measurement, were found to have a normal shaft with a normal stretched length. Diagnoses included were buried penis, webbed penis, and trapped penis. Patients ages ranged from 1 week to 13 years. FINDINGS: There were eight patients (42%) with trapped penis, and all were complications of circumcision (age 1 week to 7 months). Of nine (47%) patients with buried penis, two had been circumcised prior to diagnosis. One (5%) patient had webbed penis and one (5%) had combined buried and webbed penis. INTERVENTION: Six trapped penises were surgically repaired, and two resolved spontaneously. Five patients with buried penis had surgical repair, and two are being followed up for probable repair at age 9 to 12 months. Two were not repaired because of medical conditions or parental concerns. The webbed penis was surgically repaired as was the combined buried and webbed penis. The repair were all successful and had no complications. CONCLUSIONS: Inconspicuous penis encompasses a group of conditions in which the penis appears small but the shaft can be normal or abnormal in size. Circumcision is contraindicated in these patients until they have been evaluated by a urologist. Further study is needed to determine the natural history of these disorders and to better define which patients will benefit from surgical intervention and at what age.

Vibrio vulnificus from raw oysters. Leading cause of reported deaths from foodborne illness in Florida.

Seventy-two cases of Vibrio vulnificus infection from raw oysters were reported from 1981-1992; 36 (50%) patients died, making this infection the leading cause of reported deaths from foodborne illness in Florida. The bacterium naturally occurs in coastal waters and may contaminate legally harvested and properly handled shellfish. Infection, usually by ingestion of contaminated raw oysters, can cause severe illness especially in individuals with preexisting liver disease. They are at 80 times greater risk of illness and over 200 times greater risk of death. The case fatality rate (63%) among patients with liver diseases was over 2.5 times the rate (23%) among those without liver disease. Infections usually occurred during the warm weather months and presented as fulminant septicemia, often complicated by necrotizing cutaneous lesions. Early treatment with antibiotics, debridement and amputation when necessary may improve survival. Prevention relies upon educating patients regarding risk and thorough cooking of shellfish.