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J E Allanson

Publications and source records attributed to J E Allanson.

At least 37 records · Page 2Linked to original sources
PubMed1992

Renal tubular dysgenesis: a not uncommon autosomal recessive syndrome: a review.

Renal tubular dysgenesis is a recently recognized autosomal recessive condition characterized by short and poorly developed proximal convoluted tubules, leading to oligohydramnios, Potter sequence, and neonatal respiratory failure. We report an additional 9 cases from one pediatric center, suggesting that this syndrome is not as rare as was previously thought. Normal amniotic fluid volumes in affected pregnancies prior to the 22nd week of gestation have been documented, compromising early prenatal diagnosis. Late second trimester sonographic demonstration of oligohydramnios, with structurally normal kidneys, should suggest this diagnosis and the need for detailed post-mortem pathological examination.

Female↗
PubMed1991

Watson syndrome: is it a subtype of type 1 neurofibromatosis?

Over 20 years ago, Watson described three families with a condition characterised by pulmonary valvular stenosis, café au lait patches, and dull intelligence. Short stature is an additional feature of this autosomal dominant condition. A fourth family with Watson syndrome has since been reported. We have had the opportunity to review members of three of these four families. The clinical phenotype of Watson syndrome has been expanded to include relative macrocephaly and Lisch nodules in the majority of affected subjects, and neurofibromas in one-third of family members. Because the additional clinical findings enhance the similarity between Watson syndrome and neurofibromatosis 1, molecular linkage studies have been performed using probes flanking the NF1 gene on chromosome 17. Probe HHH202 showed the tightest linkage to Watson syndrome with a maximum lod score of 3.59 at phi = 0.0 (95% confidence limits of phi = 0.0-0.15). This suggests either that Watson syndrome and neurofibromatosis 1 are allelic, or that there is a series of contiguous genes for pulmonary stenosis, neurocutaneous anomalies, short stature, and mental retardation on 17q.

Chromosomes, Human, Pair 17↗
PubMed1990

Rubinstein-Taybi syndrome: the changing face.

Rubinstein-Taybi syndrome is a rare multiple congenital anomaly (MCA) syndrome comprising mental and growth retardation, broad thumbs and big toes, and unusual face. The classical appearance is easy to recognize. It includes downslant of the palpebral fissures, epicanthal folds, ptosis, strabismus, highly arched palate, and apparently low-set angulated ears with thickened helices. The nose has a beaked appearance, broad fleshy bridge, deviated septum that is long, protruding below the level of the nasal alae with an associated short columella. Since the typical facial phenotype may not be obvious until late childhood, I have evaluated more than 40 cases of Rubinstein-Taybi syndrome, seen at varying ages from the newborn period through infancy, childhood, and adulthood, in order to learn more about the early facial appearance.

Abnormalities, Multiple↗
PubMed1990

Neuropathy in Navajo children: clinical and epidemiologic features.

We describe a rare and apparently unique neuropathic syndrome among Navajo children living on the Navajo Reservation. Clinical features include sensorimotor neuropathy, corneal ulcerations, acral mutilation, poor weight gain, short stature, sexual infantilism, serious systemic infections, and liver derangement including Reye's syndrome-like episodes. Progressive CNS white matter lesions were diagnosed through magnetic resonance imaging. We identified 20 definite and 4 probable cases occurring between 1959 and 1986. Mean age at the time of 1st recognized symptom was 13 months (range, 1 month to 4 years 6 months). Ten individuals have died; 6 of the deaths occurred before 5 years of age. The incidence of this syndrome on the western Navajo reservation is 5 times higher than that on the eastern reservation (38 compared with 7 cases per 100,000 births). Although the etiology is unknown, this syndrome is consistent with an inborn error of metabolism, inherited in an autosomal recessive manner.

Adolescent↗
PubMed1990

Prenatal cocaine exposure and fetal vascular disruption.

The question of the potential teratogenicity of cocaine has been raised by the increasing frequency of its abuse in the United States. In previous studies, an increased incidence has been documented of spontaneous abortion, placental abruption, prematurity, intrauterine growth retardation, and neurologic deficits in the infants of women who abused cocaine. More recently, it has been suggested in studies that fetal vascular disruption accompanying maternal cocaine abuse may lead to cavitary central nervous system lesions and genitourinary anomalies. In this article, 10 children born of women who abused cocaine are described, 9 of whom have congenital limb reduction defects and/or intestinal atresia or infarction. The spectrum of anomalies associated with embryonic and fetal vascular disruption accompanying maternal cocaine abuse is thus enlarged. The specific risk for congenital anomalies accompanying maternal cocaine abuse during an individual pregnancy is unknown. However, data from these patients and the available literature suggest that counseling pregnant women concerning cocaine use should incorporate warnings about the possibility of associated embryonic or fetal vascular disruption.

Abnormalities, Drug-Induced↗
PubMed1989

Maternal translocation (9;18) with two abnormal offspring each with different chromosome derivatives.

We report a phenotypically normal woman with an apparently balanced reciprocal translocation between chromosomes 9 and 18 [46,XX,t(9;18)(p22;p11.2)], giving rise to unbalanced chromosome complements in two of her children, each of whom received a different derivative chromosome. The proband's karyotype is 46,XY,-18,+der(18), t(9;18)(p22;p11.2)mat, which results in a duplication of the distal portion of the short arm of chromosome 9 with a concomitant deletion of much of the short arm of chromosome 18. The karyotype of the proband's brother is 46, XY,-9,+der(9),t(9;18)(p22;p11.2)mat, which results in a deletion of the distal short arm of chromosome 9 and a duplication of most of the short arm of chromosome 18. The phenotype of each child is significantly different from that of his sib and is not consistent with any previously reported chromosome abnormality.

Child↗
PubMed1989

Time and natural history: the changing face.

There is a considerable body of knowledge on the changing structures of the craniofacial complex in the anthropology literature, which dates back to the late 19th century. This awareness of change in phenotype has not been emphasized in dysmorphology and incorporated into syndrome diagnosis until recently. In contrast to the anthropological data, where serial craniofacial measurements document different rates of growth in the individual structures of the craniofacial complex, awareness of the evolution of phenotype, in dysmorphology, has been based on an appreciation of a changing gestalt. This work has been carried out principally in Noonan syndrome. Noonan syndrome is a cardiofacial syndrome in which affected individuals may be short and mildly mentally retarded. In this autosomal dominant disorder, a marked change of phenotype with age from the newborn period, infancy, childhood, adolescence, and adulthood has been documented. Similar variation with age is likely to be found in many other dysmorphic syndromes. Increasing insight into the evolution of phenotypes should markedly increase the potential for diagnosis.

Adolescent↗
PubMed1988

Deletion mapping of the beta-glucuronidase gene.

GUSB, the gene for beta-glucuronidase, has been localized to the proximal long arm of chromosome 7 between 7q11.2 and 7q22. Deficiency of beta-glucuronidase results in mucopolysaccharidosis type VII (MPS VII, Sly syndrome). The enzymatic defect has been demonstrated in cultured skin fibroblasts, leukocytes and serum of affected patients. An 8-yr-old boy presented with manifestations similar to MPS VII (mental retardation, short stature, "coarse" facial appearance, mild skeletal involvement and recurrent lower respiratory tract infection) but other, discrepant abnormalities, e.g., bilateral iris colobomata and cleft palate. Normal activity of beta-glucuronidase was found in the patient's leukocytes. Chromosome analysis disclosed an interstitial deletion of 7q with one breakpoint at the interface between bands 11.22 and 11.23 and the other breakpoint within band 21.1. DNA from this patient's leukocytes was analyzed for dosage of GUSB sequences. This locus appeared to be present at the normal diploid level. These findings suggest that GUSB is not in the portion of chromosome 7 deleted in our case, narrowing the smallest region of overlap to 7q21.1----7q22. We therefore assign the beta-glucuronidase gene to 7q21.1----7q22.

Child↗
PubMed1988

Bleeding diathesis in Noonan syndrome: a common association.

The Noonan syndrome (NS) is a multiple congenital anomalies (MCA) syndrome with well-known manifestations. Excessive bleeding has been described occasionally. We report on 19 patients with NS and a bleeding diathesis. Several different defects are identified in the coagulation and platelet systems occurring singly or in combination. Clinical expression is variable. It is concluded that bleeding diatheses occur in NS at a much higher frequency than previously suspected. Consideration is given to possible relationship to underlying metabolic defects which could explain the diverse nature of the bleeding diatheses and also play a role in the pathogenesis of NS. The variety of bleeding diatheses may also reflect heterogeneity within NS. NS patients frequently undergo surgery with increased risk of bleeding. Appropriate evaluation and management is discussed. Evaluation of all NS patients and their families for bleeding disorders should provide important information about the frequency and type of bleeding diatheses which occur and perhaps help to clarify the etiology and pathogenesis of NS.

Adolescent↗
PubMed1988

G syndrome: an unusual family.

The G syndrome is a multiple congenital anomaly (MCA) syndrome of hypertelorism, hypospadias, stridor, and swallowing difficulties. Cleft lip and palate, cardiac defects, cranial asymmetry, and bowel obstruction are occasional manifestations. Family data suggest autosomal dominant inheritance. Males appear to have more serious manifestations, whereas most females with the G syndrome have a benign course and are ascertained through affected male relatives. In the family reported here, the proposita was first seen at age 7 weeks because of swallowing difficulties, stridor, and unusual facial appearance, reminiscent of the G syndrome. Evaluation of the family showed striking facial changes in her father and all four of his sibs. These five individuals had megalencephaly, hypertelorism, and a broad prominent nasal root and bridge, reminiscent of the facial appearance in the BBB syndrome. There was no evidence for dysphagia, respiratory abnormality, or hoarse voice in any other relative. These individuals with the G syndrome display two unusual manifestations. There are no males with hypospadias; the proposita has the most severe laryngotracheoesophageal symptoms. Although hypospadias is not an invariable manifestation of the G syndrome and although six females with severe dysphagia or respiratory abnormalities have been reported previously, the manifestations in this family underline the variability of this condition and provide further support that the G syndrome can be expressed with equal severity in both males and females. Although phenotypic overlap between the BBB and G syndromes has long been recognized, many still consider them to be distinct nosologic entities. The occurrence of both BBB and G syndrome in different members of the same family has been observed previously.(ABSTRACT TRUNCATED AT 250 WORDS)

Abnormalities, Multiple↗
PubMed1987

Noonan syndrome.

Explore the source record for details and available documents.

Blood Coagulation Disorders↗
PubMed1987

Y chromosome--specific DNA sequences in Turner-syndrome mosaicism.

Phenotypic females with Y-chromosomal material in their genome have an increased risk for development of gonadal malignancy. The detection and identification of Y-chromosomal material in these cases can be of critical importance for medical management. Chromosome analysis in four patients with Turner syndrome revealed the characteristic 45,X chromosome complement together with a second cell population containing a small marker chromosome (46,X, + mar). Molecular-hybridization analyses utilizing cloned, Y chromosome-specific DNA sequences were performed to determine whether Y-chromosomal material was present in each patient. Three cases contained some Y chromosome-specific sequences, whereas one case was negative with all four probes that we used. These results were compared with detailed cytogenetic studies--including G-, Q-, and G-11-banding--of the marker chromosomes. In one case in which Y chromosome-specific DNA sequences were demonstrated, the marker chromosome was G-11 negative. These results demonstrate that cytogenetic analysis alone can lead to misidentification of some Y chromosome-derived markers. The combination of cytogenetic and molecular analyses permits a more accurate characterization of anomalous Y chromosomes and in turn provides additional information that can be crucial to the correct medical management of Turner-syndrome patients.

Chromosome Banding↗
PubMed1986

Germinal mosaicism in Apert syndrome.

Two sisters with Apert acrocephalosyndactyly syndrome born to normal unrelated parents are described. Paternity studies show that the probability of paternity is 99.3%. This report appears to represent the first known example of germinal mosaicism in Apert syndrome.

Acrocephalosyndactylia↗
PubMed1986

Growth curves for height in Noonan syndrome.

Growth retardation is a relatively consistent feature of Noonan syndrome but a standardized growth curve for height has never been calculated. Analysis of retrospective growth data on 112 patients with Noonan syndrome has permitted the establishment of preliminary reference growth standards for height for males and females. The results confirm the clinical impression that short stature among this group of patients occurs uniformly and is independent of chronological age. Various factors which may modify this are considered.

Adolescent↗
PubMed1986

Obstetric and gynecologic problems in women with chondrodystrophies.

Despite the growing body of knowledge on the natural history of various chondrodystrophies, little is known of the associated obstetric and gynecologic problems. The authors have surveyed by questionnaire 150 women with chondrodystrophies after a request by the women of Little People of America and Little People of Canada that a survey of their members be carried out. It was found that some obstetric and gynecologic problems are common to all women with short stature. There is an increased incidence of menstrual complications, problems with certain methods of contraception, and evidence of reduced fertility. In addition, delivery should almost always be by cesarean section under general anesthesia. There are, however, some unique complications in specific chondrodystrophies in the present study group. Women with achondroplasia have premature menopause and an increased incidence of leiomyomata; women with osteogenesis imperfecta have late menarche; and women with pseudoachondroplasia and cartilage hair hypoplasia have long menstrual cycles.

Adolescent↗
PubMed1985

Noonan phenotype associated with neurofibromatosis.

We report on four patients with neurofibromatosis and manifestations of Noonan syndrome including short stature, ptosis, "midface hypoplasia," apparently short webbed neck, learning disabilities, and weakness. No family history of neurofibromatosis was present in any case. Average paternal and maternal age at birth was 37 and 28 years, respectively, suggestive of a new mutation. The presence of a distinct phenotype and hypotonia in these patients with neurofibromatosis is suggestive of a new separate disorder.

Adult↗