Living with phenylketonuria: perspectives of patients and their families.

This study surveyed PKU patients and their primary caretakers to assess their current management practices, the barriers to effective management, and the potential utility of a home monitor in managing PKU. A survey instrument was mailed to caretakers of all 50 patients with PKU in Utah between the ages of 2 and 18 years in 1997 (response rate 64%). It included separate components for caretakers and patients aged 10 to 18 years. Although there was uneven compliance with recommended practices, caretakers universally recognized the negative consequences of not adhering to the low-protein diet. There was, however, disagreement regarding such consequences among the older children surveyed. The primary obstacles cited to better adherence were time constraints and stress associated with food preparation and record-keeping, and the restrictions imposed on social life. Phenylalanine test results were regarded as the principal signal for the need for dietary adjustment. Despite the facts that obstacles to dietary adherence are multifaceted and that no single intervention would therefore serve as a panacea, a large majority of respondents believed a home monitor would facilitate better management of PKU through more regular and timely feedback.

Previously apparently undescribed autosomal recessive MCA/MR syndrome with light fixation, retinal cone dystrophy, and seizures: the M syndrome.

We report on two sisters from healthy families with a syndrome of severe developmental delay, ataxia, impaired social interaction, a seizure disorder with early onset but without epileptiform electroencephalogram changes, and a striking light-fixating behavior which was associated with retinal cone dystrophy. Additionally, they have minor anomalies including peripheral iris hypoplasia, bluish sclerae, mild anteversion of nostrils, micrognathia, ear anomalies, broad halluces and thumbs, hypoplastic toenails, short perineal body, "Mongolian spots," mild hirsutism, hypoplastic ridges in the hypothenar area, and distal axial triradii. Growth and general health are normal in both, but one also had tetralogy of Fallot and vesicoureteral reflux. Because this condition appears to be previously undescribed we postulate a new autosomal recessive disorder with light-fixating behavior and retinal cone dystrophy as leading symptom.

Testing for inborn errors of metabolism in the acutely ill newborn.

The differential diagnosis of the acutely ill newborn should include inborn errors of metabolism along with much more common conditions such as sepsis and hypoxemia. Testing recommendations, which can take place simultaneously with other studies, are presented for the evaluation of inborn errors in acutely ill newborns. Initial hospital-based tests include arterial blood gases, glucose, electrolytes, urinalysis, complete blood count, and cultures. The results from these initial tests are used to categorize the clinical presentation into one of several categories, and each category in turn serves to direct further testing in an efficient manner. Definitive diagnosis often requires referral to a pediatric specialist, as well as testing available only through reference and research laboratories. Transfer to a tertiary care facility may be advisable when evidence for an inborn error is found.

Children and adolescents with neurofibromatosis 1: a behavioral phenotype.

Twenty 6- to 17-year-old children with neurofibromatosis 1. (NF1) were compared to 20 age- and sex-matched siblings on a wide range of neuropsychological and behavioral dimensions. In familial cases, diagnostic status was confirmed by gene linkage with greater than 98% accuracy. Visual examinations that included assessments of visual evoked responses (VER) were performed on subjects with NF1. Forty-two percent of NF1 subjects had abnormal VER and underwent magnetic resonance imagery or computed tomography scans of the brain. On a variety of skills, subjects with NF1 performed more poorly than unaffected siblings. Children with NF1 were found to be less competent on measures of cognitive, language, and motor development, visual-spatial judgment, visual-motor integration, and academic achievement. Learning disabilities were common in children with NF1. Parents and teachers reported that NF1 subjects had internalizing problems and difficulty interacting with peers. A behavioral phenotype for NF1 and recommendations for preventative interventions are proposed.

Opitz syndrome is genetically heterogeneous, with one locus on Xp22, and a second locus on 22q11.2.

Opitz syndrome (OS, McKusick 145410) is a well described genetic syndrome affecting multiple organ systems whose cardinal manifestations include widely spaced eyes and hypospadias (Fig. 1). It was first reported as two separate entities, BBB syndrome, and G syndrome. However, subsequent reports of families in which the BBB and G syndrome segregated within a single kindred suggested that they were a single clinical entity. Although the original pedigrees were consistent with X-linked and autosomal dominant inheritance, male-to-male transmission in subsequent reports suggested that OS was inherited as an autosomal dominant trait. Here we report that OS is a heterogeneous disorder, with an X-linked and an autosomal locus. Three families were linked to DXS987 in Xp22, with a lod score of 3.53 at zero recombination. Five families were linked to D22S345 from chromosome 22q11.2, with a lod score of 3.53 at zero recombination. This represents the first classic multiple congenital anomaly syndrome with an X-linked and an autosomal form.

Strong correlation of elastin deletions, detected by FISH, with Williams syndrome: evaluation of 235 patients.

Williams syndrome (WS) is generally characterized by mental deficiency, gregarious personality, dysmorphic facies, supravalvular aortic stenosis, and idiopathic infantile hypercalcemia. Patients with WS show allelic loss of elastin (ELN), exhibiting a submicroscopic deletion, at 7q11.23, detectable by FISH. Hemizygosity is likely the cause of vascular abnormalities in WS patients. A series of 235 patients was studied, and molecular cytogenetic deletions were seen in 96% of patients with classic WS. Patients included 195 solicited through the Williams Syndrome Association (WSA), plus 40 clinical cytogenetics cases referred by primary-care physicians. Photographs and medical records of most WSA subjects were reviewed, and patients were identified as "classic" (n = 114) or "uncertain" (n = 39). An additional 42 WSA patients were evaluated without clinical information. FISH was performed with biotinylated ELN cosmids on metaphase cells from immortalized lymphoblastoid lines from WSA patients and after high-resolution banding analysis on clinical referral patients. An alpha-satellite probe for chromosome 7 was included in hybridizations, as an internal control. Ninety-six percent of the patients with classic WS showed a deletion in one ELN allele; four of these did not show a deletion. Of the uncertain WS patients, only 3 of 39 showed a deletion. Of the 42 who were not classified phenotypically, because of lack of clinical information, 25 patients (60%) showed a deletion. Thirty-eight percent (15/40) of clinical cytogenetics cases showed an ELN deletion and no cytogenetic deletion by banded analysis. These results support the usefulness of FISH for the detection of elastin deletions as an initial diagnostic assay for WS.

Opitz (BBB/G) syndrome: oral manifestations.

We studied a new case of the G (Opitz BBB/G) syndrome in a 12-year-old boy. Several relatives had partial manifestations of the disorder. A comprehensive dental evaluation of the propositus was conducted; included is, to our knowledge, the first published cephalometric analysis of a G syndrome patient. We reviewed 139 cases of the G syndrome; 48 of them had at least one oral abnormality. These included clefting, micrognathia, ankyloglossia, and high-arched palate. Male G syndrome patients are more likely to have oral anomalies than affected females.

Bone mineral status in children with phenylketonuria--relationship to nutritional intake and phenylalanine control.

The mineral status in phenylketonuria (PKU) was measured by single-photon densitometry of the distal radius and plasma concentrations in 26 subjects. Bone mineral content increased normally with age in the younger children despite strict dietary restrictions. Subjects aged greater than 8 y, however, were frequently below the normal curve for bone mineral content. Blood phenylalanine concentrations were significantly higher in the older group of subjects and this correlated with decreased compliance with dietary prescriptions. PKU children had significantly decreased plasma concentrations of alkaline phosphatase, magnesium, and parathyroid hormone. Subnormal concentrations of plasma zinc and plasma and red blood cell (RBC) copper were common, but RBC zinc was normal. We conclude that compliance with dietary therapy for PKU is associated with normal bone mineral development in young children. Older patients with PKU who follow the diet less carefully are at risk for low bone mineral content.

Late-onset ornithine transcarbamylase deficiency in male patients.

We report on 21 male patients who presented after 28 days of age with ornithine transcarbamylase (OTC) deficiency, which we define as late-onset OTC deficiency. These patients appeared normal at birth, but irritability, vomiting, and lethargy, which were often episodic, later developed. The age at presentation ranged from 2 months to 44 years. Biochemical testing revealed hyperammonemia, hyperglutaminemia, hypocitrullinemia, increased urinary orotate excretion, and decreased liver OTC activity measured in vitro, which ranged from 0% to 15% of normal. Male patients who were older at presentation had a somewhat different pattern of presenting symptoms and were more likely to die. These data illustrate the phenotypic variability of OTC deficiency. Unexplained episodes of repetitive or protracted vomiting in association with progressive alterations in behavior or neurologic findings should suggest the diagnosis of a urea cycle defect (or another symptomatic inborn error of metabolism), regardless of the age or medical history of the patient.

Adults with Williams syndrome.

Reports of adults with Williams syndrome (WS) have been rare. We have evaluated 13 adult WS patients and reviewed 16 case reports of WS in patients older than age 16 years. Adults in our study had progressive multisystem medical problems. Cardiovascular complications were common (12/13) including hypertension (8), supravalvular aortic stenosis (9), aortic hypoplasia (3), pulmonic artery stenosis (4), peripheral stenoses (3), and mitral valve prolapse (2). Joint limitation (12/13) was progressive, often accompanied by kyphoscoliosis and lordosis. Recurrent urinary tract infections in 6 individuals led to radiologic studies showing urethral stenosis in 2, and bladder diverticula and vesicoureteral reflux in 3. Gastrointestinal problems included obesity (5), chronic constipation (7), diverticulosis (3), and cholelithiasis (4). Hypercalcemia was documented in 5 patients, although others had hypercalcemic symptoms (abdominal pain, polyuria, and constipation). One 45-year-old man had parathyroid hyperplasia. Previous reports likewise document significant morbidity. Thus, Williams syndrome in an adult appears to dictate aggressive evaluation and monitoring. Investigation of calcium metabolism should be undertaken in each adult WS patient.

Hypothesis for development of a behavioral phenotype in Williams syndrome.

We investigated the natural history of Williams syndrome (WS), including physical characteristics and cognitive, academic language, sensory integration, and adaptive and maladaptive behavior in 32 patients (age 3 to 30 years). These patients were available for psychoeducational testing, parent interview, medical and educational record review, and behavioral observation. Thirty-seven nonlocal individuals (age 8 months to 31 years) were not tested but data on history and development, sensory integration, adaptive and maladaptive behavior were collected resulting in a total sample of 69. The unique constellation of physical manifestations and associated clinical problems in WS contributes to a characteristic behavioral phenotype of 6 factors beginning in infancy with development of salient attachment behaviors. Later a key issue affecting the learning abilities of both the school-aged child and adult with WS was an inadequate development in the use of tools. Theoretical constructs from developmental behavioral genetics, attachment theory, operant conditioning, neuropsychology, and psychosocial theory considered interactively offer explanations for these characteristics.

Prenatal diagnosis and heterozygote detection by DNA analysis in ornithine transcarbamylase deficiency.

This report summarizes our experience with DNA analysis using a complementary DNA probe for ornithine transcarbamylase in 24 individuals or families with deficiency of this enzyme. In four cases, including three reported elsewhere, a Taql restriction site alteration directly detected the mutation. In 10 additional cases, only an affected male was available, and results of DNA analysis using the Taql enzyme were normal. In 10 cases, family studies were performed with the use of restriction fragment length polymorphisms. Prenatal diagnostic studies were performed for three informative pregnancies, and two affected male fetuses were identified. Analysis of two restriction fragment length polymorphisms, Mspla and BamHl, was informative in 14 of 19 (74%) known carrier females and in 21 of 35 (60%) females (the total number studied). One female previously predicted to be a noncarrier by protein-loading test was determined to be a carrier by analysis of restriction fragment length polymorphisms. The frequency of Taql site alterations was 4 of 24 families (17%). These data illustrate the importance of DNA analysis, pedigree analysis, and biochemical testing in families with ornithine transcarbamylase deficiency to detect carriers and establish the diagnosis prenatally.

Congenital diaphragmatic hernia, coarse facies, and acral hypoplasia: Fryns syndrome.

We describe five patients with Fryns syndrome. Four presented with diaphragmatic hernia and died in the neonatal period. One did not have diaphragmatic involvement and survived but is severely mentally retarded. All patients had "coarse" faces, microretrognathia, macrostomia, and distal digital hypoplasia. In addition to previously reported traits, our patients had clinical manifestations that have not previously been described, including omphalocele, broad clavicles, Hirschsprung "disease," and anal anomalies. The condition was detected antenatally in three of the cases. The patients include two sib pairs, further supporting autosomal recessive inheritance.

Natural history of Williams syndrome: physical characteristics.

The natural history of Williams syndrome, including medical complications, growth patterns, and problems in adulthood, was investigated. A growth pattern characterized by delay in the first 4 years of life, catch-up growth in childhood, and low ultimate adult height was found. Despite multiple medical problems in infancy, including feeding problems, failure to thrive, colic, and otitis media, mean age at diagnosis was 6.4 years. Developmental disabilities and cardiovascular disease were the major concerns in childhood. The older children developed progressive joint limitation and hypertonia. Adult patients were handicapped by their developmental disabilities. Hypertension, and gastrointestinal and genitourinary problems occurred frequently. Independent living and competitive employment were limited less by the individual's physical problems than by the psychologic and adaptive limitations. Williams syndrome is a progressive disorder with multisystem involvement.

Prenatal screening and pregnant women's attitudes toward the abortion of defective fetuses.

We studied the attitudes of 490 pregnant women toward the abortion of defective fetuses. Three hundred of these women were participating in a prenatal screening program for neural tube defects. Although theoretical accounts of the effects of behavior on attitude would suggest that participation in a screening program would affect abortion attitudes, evidence in support of such an association was weak. The overwhelming majority of women, regardless of whether they had participated in the screening program, believed that women are justified in having an abortion in the face of fetal abnormality. There was a sharp increase in the number of screening program participants who said they would have an abortion when the probability of the fetus being affected with a neural tube defect rose from 95 per cent to 100 per cent.

Assessment of risk by pregnant women: implications for genetic counseling and education.

PIP: One of the central elements of genetic counseling is the transmission of quantitative information concerning risks of defects in an unborn child from counselor to client. In order to investigate this subject, the authors studied the understanding of numeric and nonnumeric descriptions of genetic risk by 190 pregnant women. Specifically, 3 risk issues were explored: whether women were able to interpret numeric risks as %s whether shifting denominators affected risk assessment; and the comparative assessment of risk of birth defects in general, and the risk of a neural tube defect, (NTDS) in particular. Respondents were much less likely to assign the correct % equivalent to risk information when the denominator was 1,000 rather than 100. The ability to correctly identify % equivalents affected respondents' quantitative assessment of the frequency of neural tube defects. Shifting the denominator from 100 to 1,000 however, did not affect women's quantitative assessment of the rarity of birth defects. In general, the respondents preserved the relative risk of birth defects and neural tube defects in their choice of descriptive terms. The majority of women evaluated serious birth defects as occurring "often" or "occasionally" and NTDS as occurring "rarely" or "very rarely."^ieng

What participants understand about a maternal serum alpha-fetoprotein screening program.

We investigated the knowledge of pregnant women participating in a maternal serum alphafetoprotein (MSAFP) screening program for the detection of neural tube defects (NTDs) in the fetus. Women participating in the screening program scored higher on two knowledge tests than a comparison group of pregnant women who were not offered screening. However, there were substantial gaps in the knowledge base of women in the program, as measured by one of the tests. Women did not misinterpret a negative test result to mean that the test had identified a potential problem with the fetus; instead, there is a suggestion that they tended to interpret a negative result too positively, as an assurance that the baby was healthy in all respects.

KIE: Pregnant women participating in a maternal serum alpha-fetoprotein (AFP) screening program for the detection of fetal neural tube defects were interviewed to evaluate their understanding of the test, the defects, and the meaning of test results. Although women participating in the screening program scored higher on two knowledge tests than a comparison group not offered screening, there were substantial gaps in knowledge. Poor performance on the free response test (in which definitions of terms were requested) raises concerns about the adequacy of the women's consent to screening. They understood that a positive test result would entail having to make a decision about abortion, but seemed to have interpreted a negative test as an assurance that the baby was healthy in all respects.