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Biomedical subjects

R A Saul

Publications and source records attributed to R A Saul.

At least 19 recordsLinked to original sources
PubMed2001

22q13 deletion syndrome.

We have recently collected clinical information on 37 individuals with deletion of 22q13 and compared the features of these individuals with 24 previously reported cases. The features most frequently associated with this deletion are global developmental delay, generalized hypotonia, absent or severely delayed speech, and normal to advanced growth. Minor anomalies include dolicocephaly, abnormal ears, ptosis, dysplastic toenails, and relatively large hands. As with many terminal deletions involving pale G-band regions, the deletion can be extremely subtle and can go undetected on routine cytogenetic analysis. In fact, 32% of the individuals in our study had previous chromosome analyses that failed to detect the deletion. Eight of 37 individuals had deletion of 22q13 secondary to an unbalanced chromosome translocation. In the newborn, this deletion should be considered in cases of hypotonia for which other common causes have been excluded. In the older child, this syndrome should be suspected in individuals with normal growth, profound developmental delay, absent or delayed speech, and minor dysmorphic features. We recommend high-resolution chromosome analysis and fluorescence in situ hybridization studies, or molecular analysis to exclude this diagnosis.

Abnormalities, Multiple↗
PubMed1999

Down syndrome clinic in a semi-rural setting.

We established a multidisciplinary clinic for Down syndrome patients and their families. Over a 20-month period, we saw 49 patients for a total of 79 patient visits. We were able to address health care, psychosocial, educational, and financial issues for these individuals with a diverse team of professionals and parent advocates. Some of these issues would probably not be identified during routine health care. The success of the clinic demonstrates the ability to establish such a venture in a semi-rural, nonacademic medical center setting.

Adolescent↗
PubMed1998

Constitutional and mosaic large NF1 gene deletions in neurofibromatosis type 1.

A set of neurofibromatosis type 1 (NF1) patients was screened for large NF1 gene deletions by comparing patient and parent genotypes at 10 intragenic polymorphic loci. Of 67 patient/parent sets (47 new mutation patients and 20 familial cases), five (7.5%) showed loss of heterozygosity (LOH), indicative of NF1 gene deletion. These five patients did not have severe NF1 manifestations, mental retardation, or dysmorphic features, in contrast to previous reports of large NF1 deletions. All five deletions were de novo and occurred on the maternal chromosome. However, two patients showed partial LOH, consistent with somatic mosaicism for the deletion, suggesting that mosaicism may be more frequent in NF1 than previously recognised (and may have bearing on clinical severity). We suggest that large NF1 deletions (1) are not always associated with unusual clinical features, (2) tend to occur more frequently on maternal alleles, and (3) are an important mechanism for constitutional and somatic mutations in NF1 patients.

Adult↗
PubMed1995

Prenatal diagnosis of mosaic 4p- in a fetus with trisomy 21.

Mosaicism for the Wolf-Hirschhorn syndrome, del(4)(p16), is extremely rare and has not been reported in association with a numerical chromosome abnormality. We report the prenatal diagnosis of mosaic del(4)(p16) and non-mosaic trisomy 21 in a 16-week female fetus. The pregnancy ended in spontaneous abortion at 34 weeks secondary to fetal demise. The fetus had features of both 4p- and trisomy 21.

Adult↗
PubMed1993

Brachmann-de Lange syndrome: diagnostic difficulties posed by the mild phenotype.

We describe 4 patients with facial changes of Brachmann-de Lange syndrome but without limb defects. Mental retardation ranged from moderate to severe and the degree of prenatal and postnatal growth deficiency was variable. These patients exemplify the diagnostic difficulties and counseling dilemmas posed by the mild Branchmann-de Lange phenotype. The relationship of the mild phenotype to the full syndrome will not be understood until the pathogenetic or causal factor(s) are delineated.

Adult↗
PubMed1993

Molecular genetic advances in fragile X syndrome.

The fragile X syndrome is recognized as the most common heritable condition resulting in mental retardation. The disabilities are substantial, and therefore early detection is mandatory to assist with reproductive counseling of families in which the fragile X syndrome has occurred. Highly accurate, direct DNA diagnostic testing can now be performed to diagnose the fragile X syndrome without the involvement of individual family members, as was the situation with the use of DNA linkage analysis. Such testing is rapidly becoming a standard diagnostic tool for screening of individuals with suspected fragile X syndrome, of potential unaffected carriers, and of patients with undefined mental retardation. Fragile X testing should be considered for all children with developmental delay of unknown cause. Autistic children will occasionally be found to have mutations in FMR-1. Detection of affected individuals will allow early intervention for these individuals and will assist families with their reproductive decisions (including prevention) in subsequent offspring. An understanding of the molecular genetics of fragile X syndrome has resulted in the resolution of the Sherman paradox and is the first molecular characterization of a chromosomal fragile site, a finding that almost certainly will be important in understanding the cause of chromosomal rearrangements involving fragile sites. In addition, molecular details of the fragile X mutations have yielded insight into "heritable unstable elements," of which the fragile X chromosome is one of the first characterized examples. Thus a similar molecular mechanism involving a trinucleotide repeat may explain the genetics of myotonic dystrophy and spinal-bulbar muscular atrophy (Kennedy disease); it seems reasonable to assume that other genetic diseases also may result from disruption of genes by inherited unstable elements.

DNA↗
PubMed1992

Disseminated Nocardia transvalensis infection: an unusual opportunistic pathogen in severely immunocompromised patients.

Nocardia infections are infrequently recognized in humans. Nocardia species may cause severe life-threatening infections among immunocompromised patients and have been reported to cause actinomycotic mycetomas, primarily in tropical areas. Two severely immunocompromised patients had disseminated N. transvalensis infections. One had underlying X-linked variant chronic granulomatous disease and died of disseminated N. transvalensis infection, which was diagnosed only at postmortem examination. The second patient developed N. transvalensis pneumonia within 3 months of undergoing renal transplantation and died of disseminated mixed Pseudallescheria boydii and N. transvalensis infections. Thus, N. transvalensis may cause invasive and potentially fatal pulmonary and disseminated infections. Accordingly, clinical microbiology laboratories should become proficient in identifying this uncommon aerobic actinomycete.

Adult↗
PubMed1991

DNA fingerprinting: the utilization of minisatellite probes to detect a somatic mutation in the proteus syndrome.

Syndromes with localized or segmental abnormalities have been proposed to be the result of a somatic mutation leading to the presence of somatic mosaicism in the tissue. The Proteus syndrome, with its hemihypertrophy, macrodactyly and exostoses, has features which would indicate that the phenotype results from such events. The success of utilizing DNA fingerprint probes to detect somatic mutations in cancer raised the possibility that a similar approach might be successful in an investigation of two patients with the Proteus syndrome. Single band differences were detected with the probe 33.6 in a pair of monozygotic twins discordant for Proteus and in a comparison of tissue from normal and affected areas in another patient. These findings would appear to confirm the hypothesis that the Proteus syndrome results from a somatic mutation. Furthermore, the results indicate that DNA fingerprinting may offer a valuable technique for identifying probes for investigations of similar syndromes.

Abnormalities, Multiple↗
PubMed1990

A "new" skeletal dysplasia in two unrelated boys.

We report on 2 unrelated boys with similar physical and radiographic findings that may represent a "new" skeletal dysplasia. Findings in common include early speech delay, short stature, frontal bossing with a depression over the metopic suture, a narrow nasal root with beaked nose, midfacial hypoplasia with relatively prominent eyes, and brachydactyly with blunt fingers. Radiographic findings include mild irregularities of the vertebral bodies, hypoplasia of the odontoid process, short phalanges with increased distal width, coning and sclerosis of several epiphyses, and overtubulation of the long bones. Although these patients share some manifestations with the floating-harbor syndrome (Robinson et al.: J Pediatr 113:703-706, 1988), their radiographic changes are distinctive and are not suggestive of a recognized skeletal dysplasia syndrome.

Bone Diseases, Developmental↗
PubMed1982

Hyperplasia of the myenteric plexus. Its association with early infantile megacolon and neurofibromatosis.

An infant with cutaneous criteria for neurofibromatosis had hyperplasia of the intestinal myenteric plexus and a clinical presentation mimicking Hirschsprung's disease. Many of his phenotypic features are also found in multiple endocrine neoplasia type IIb, a condition in which hyperplasia of the myenteric plexus is common. This case illustrates the overlapping nature of neural crest-derived conditions and the variable presentation of megacolon (ganglionic or aganglionic) in infancy.

Humans↗
PubMed1982

Caffey's disease revisited. Further evidence for autosomal dominant inheritance with incomplete penetrance.

A family with six members affected with Caffey's disease (infantile cortical hyperostosis) demonstrates marked variability in expression and incomplete penetrance for this autosomal dominant condition. Twenty-five additional instances of familial Caffey's disease (with a total of 104 persons affected) are reviewed. From the 1940s to 1960s, sporadic cases of Caffey's disease occurred more commonly than did familial cases and probably represented environmentally produced phenocopies. Such isolated cases are rarely seen today. FAmilial Caffey's disease differs in several aspects from the sporadic type, having an earlier onset of disease (24% at birth), less frequent mandibular involvement, and more frequent lower-extremity involvement. Cases of Caffey's disease detected today should have appropriate radiologic testing of other family members to search for evidence of disease. Prompt recognition allows for conservative management of this usually self-limited condition.

Humans↗