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Biomedical subjects

S B Cassidy

Publications and source records attributed to S B Cassidy.

At least 19 recordsLinked to original sources
PubMed1992

Prader-Willi syndrome in a brother and sister without cytogenetic or detectable molecular genetic abnormality at chromosome 15q11q13.

We report on a 12-year-old boy and his 7-year-old sister with the Prader-Willi syndrome. They both had severe initial hypotonia with feeding problems and later developed an increasing appetite. Both sibs have almond-shaped eyes, triangular mouth, hypogonadism, retarded growth, and mental retardation. An older brother suffered from severe hypotonia and died at 7 days of age. The children have normal chromosomes by high-resolution technique and have inherited the same chromosomes 15 short arm polymorphisms from their parents. The family was informative for one of four DNA markers specific for the 15q11q13 region. No deletion was found using this marker. The parents were healthy and unrelated. Autosomal recessive inheritance or a paternally inherited submicroscopic deletion are possible explanations for the sib occurrence in this family.

Adult↗
PubMed1992

7p deletion syndrome: an adult with mild manifestations.

Deletion of 7p results in a wide spectrum of congenital abnormalities and minor facial and hand anomalies, often including craniosynostosis. We report on the oldest recognized patient with this disorder, a 24-year-old woman with an interstitial deletion from p15.3-p21.2 or p21.3. The manifestations in this patient are milder than those of previously described patients, and include borderline mental retardation, short stature, minor facial anomalies, and several skeletal changes. The absence of craniosynostosis in this patient is noteworthy, given previous suggestions that there is a specific locus for this finding in the 7p region. Twelve cases of 7p deletion, in which the missing segment overlaps that of the current case, are reviewed. This case delineates a broader spectrum for patients with 7p deletion syndrome.

Abnormalities, Multiple↗
PubMed1992

Trisomy 15 with loss of the paternal 15 as a cause of Prader-Willi syndrome due to maternal disomy.

Uniparental disomy has recently been recognized to cause human disorders, including Prader-Willi syndrome (PWS). We describe a particularly instructive case which raises important issues concerning the mechanisms producing uniparental disomy and whose evaluation provides evidence that trisomy may precede uniparental disomy in a fetus. Chorionic villus sampling performed for advanced maternal age revealed trisomy 15 in all direct and cultured cells, though the fetus appeared normal. Chromosome analysis of amniocytes obtained at 15 wk was normal in over 100 cells studied. The child was hypotonic at birth, and high-resolution banding failed to reveal the deletion of 15q11-13, a deletion which is found in 50%-70% of patients with PWS. Over time, typical features of PWS developed. Molecular genetic analysis using probes for chromosome 15 revealed maternal disomy. Maternal nondisjunction with fertilization of a disomic egg by a normal sperm, followed by loss of the paternal 15, is a likely cause of confined placental mosaicism and uniparental disomy in this case of PWS, and advanced maternal age may be a predisposing factor.

Adult↗
PubMed1991

New syndrome: mother and son with hypertelorism, downslanting palpebral fissures, malar hypoplasia, and apparently low-set ears associated with joint and scrotal anomalies.

We report on a mother and son with a similar syndrome of hypertelorism and telecanthus, epicanthal folds, downslanting palpebral fissures, ptosis, broad nasal bridge, malar hypoplasia, thin upper lip, smooth philtrum, and apparently low-set prominent ears. The son also has a hypoplastic shawl scrotum, cryptorchidism, and genu valgum. His language development was delayed at 18 months, but subsequently improved and was normal at age 3. The mother has the additional findings of marked cubitus valgus, hyper-extensible joints, dull normal intelligence and a bleeding diathesis. This pattern of multiple congenital anomalies may represent a new syndrome.

Abnormalities, Multiple↗
PubMed1991

Hand and foot length in Prader-Willi syndrome.

Small hands and feet (acromicria) are often cited as manifestations in the Prader-Willi syndrome (PWS), but it has been our experience that these are not universal findings. To address this issue, we obtained longitudinal and cross-sectional data, retrospectively and prospectively, including height, hand length, and foot length, on 56 patients with PWS who are followed in the multidisciplinary PWS clinic at the University of Connecticut Health Center. Hand and foot lengths were plotted using two published sets of normative data. In addition, height age was calculated on each measurement of stature so that the corresponding hand and foot measurements could be compared to those expected for height, rather than age, as many PWS individuals are short. Foot length was proportionately smaller than hand length in all individuals; this difference was more striking in females. By age 12 years, almost all individuals had a foot length less than 25th centile for chronological age and less than 50th centile for height age. Female hand length was also less than 25th centile for chronological by age 12 years and less than 50th centile for height age in almost all cases. Male hand length data appeared to fall more within the normal range until adulthood, although fewer data were available. Black individuals with PWS had relatively larger hands and feet than their Caucasian counterparts. Many people with PWS had hand and foot lengths which fell within the normal range, particularly those under the age of 12 years and those whose height was greater than 50th centile for age.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Chromosome 7p--syndrome: craniosynostosis with preservation of region 7p2.

Deletion of a portion of the short arm of chromosome 7 is associated with a recognizable phenotype which often includes craniosynostosis. Recent reports have suggested that craniosynostosis occurs only if there is a deletion involving band 7p21 or the segment distal to that band. We report on a boy who had an interstitial deletion of 7p, not involving band 7p21 or the segment distal to that band, who nevertheless had craniosynostosis. Thus, it appears that the determination of craniosynostosis in this syndrome is more complicated than has been suggested previously.

Abnormalities, Multiple↗
PubMed1990

Physical features of Prader-Willi syndrome in neonates.

A retrospective study of 16 patients was undertaken to identify physical features that may typify neonates with Prader-Willi syndrome. Several features known to be typical of Prader-Willi syndrome in early infancy were confirmed, including hypotonia and genital hypoplasia. A number of features that have not previously been emphasized as characterizing Prader-Willi syndrome were also identified, most notably abnormal cry and, in males, signs of genital hypoplasia but with an apparently normal phallus. Other features included disproportionately large head circumference, disproportionately large anterior fontanelle, mild micrognathia, mild anomalies of the gingivae or alveolar ridges, and changes in the appearance of the skin. Appreciation of these features may assist the pediatrician in recognizing the child with Prader-Willi syndrome during the neonatal period, before the appearance of better-known findings of later onset, such as obesity and acromicria.

Anthropometry↗
PubMed1990

Cephalometric analysis of the Prader-Willi syndrome.

The Prader-Willi syndrome (PWS) is characterized by short stature, mild mental retardation, and a characteristic face. Approximately 75% of all patients have a del (15q). Cephalometric roentgenograms of 20 PWS patients of both sexes (12 adults, 8 children, age 4.5-50.0 years) were analyzed to determine if the facial appearance is reflected in changes in the bony architecture, a characteristic which might be useful in diagnosis and/or dental treatment of these individuals. PWS subjects were compared with chronologic age and sex-matched control individuals derived from the Denver Growth study using 52 point computer analyzed lateral head-plate tracings performed by the same individual (RS). The mean Z-score differences for mandibular and maxillary total length, ramus height, mandibular corpus length, posterior facial height, and mid-facial height were all significantly smaller in greater than 65% of the PWS subjects; this was more evident in the PWS children. The Z-score difference for posterior cranial base was very large in most PWS adults and children whereas lower facial height was small or normal in all subjects. No statistical difference in mean Z-score measurements was found for all these measures in PWS subjects with or without the 15q chromosome deletion. The overall small bony structures contrast with the relatively large soft tissue draping seen especially in obese adults. The data suggest that a characteristic bony model might be created for PWS which could be of use in diagnosis and in the treatment of PWS patients by their orthodontist.

Adolescent↗
PubMed1990

Tuberous sclerosis in pregnancy.

Tuberous sclerosis is an autosomal dominant disorder of hamartoma formation in which manifestations may occur in skin, brain, and viscera. In the past, it was believed that the typical presentation included seizures, mental retardation, and facial angiofibromas ("adenoma sebaceum"). This disorder is now recognized to show wide variability of expression. There are only four cases of tuberous sclerosis in pregnancy in the literature. Two of these had favorable maternal and fetal outcomes and the remaining two presented with serious maternal and fetal complications. These included acute intra-abdominal bleeding due to a ruptured renal tumor, which led to renal failure requiring hemodialysis, and severe preeclampsia with pathologically enlarged kidneys noted at the time of cesarean section. This study presents two more cases of tuberous sclerosis in pregnancy. The first case had renal involvement with bleeding into a renal cyst, renal failure, preeclampsia, and severe intrauterine growth retardation. The second case was complicated by preterm premature rupture of the membranes and preterm labor. Renal involvement appears to be the single most important prognostic factor in pregnancies with tuberous sclerosis. Renal evaluation should be performed in any patient who presents for preconceptional counseling.

Adult↗
PubMed1989

Epiphyseal dysplasia with coxa vara, microcephaly, and normal intelligence in sibs: expanded spectrum of Lowry-Wood syndrome?

We report on a brother and sister with epiphyseal dysplasia and coxa vara, microcephaly, and short stature. This constellation of findings similar to that found in the Lowry-Wood syndrome (Epiphyseal dysplasia, microcephaly, short stature, and mental retardation). In the sibs we describe, mental retardation is not apparent, and they have the additional finding of developmental coxa vara. Despite these 2 exceptions, this family probably represents the same disorder described by Lowry and Wood (Clinical Genetics 8:269-274, 1975), and serves to expand the spectrum of the syndrome to include coxa vara. It is also possible that these sibs represent a previously undescribed syndrome, most likely with autosomal recessive inheritance.

Bone Diseases, Developmental↗
PubMed1989

Prader-Willi syndrome.

People with Prader-Willi syndrome exhibit infantile hypotonia and failure to thrive, genital hypoplasia, childhood-onset obesity, mental deficiency and behavioral abnormalities, hypogonadism, short stature, and characteristic dysmorphology. In over half the affected individuals, prometaphase chromosome analysis reveals a small interstitial deletion of chromosome 15q, del 15(q11-q12); with most of the remaining patients showing apparently normal chromosomes. Molecular genetic technology is currently being applied to the relevant region of chromosome 15 to determine if there is etiologic heterogeneity and to seek a consistent diagnostic marker. Diagnosis at this time is primarily based upon clinical criteria.

Adolescent↗
PubMed1989

Internal carotid artery aneurysm: a vascular manifestation of type IV Ehlers-Danlos syndrome.

Aneurysms of the distal internal carotid artery (ICA) can be difficult to manage. When seen in a patient with Ehlers-Danlos Syndrome, type IV (EDS-Type IV), the complexity of the problem is greatly increased. Proximal ICA ligation in the presence of an intact circle of Willis and adequate collateral circulation is a reasonable and safe approach. We recommend the liberal use of duplex scanning and intravenous digital angiography in patients with EDS, and plan to use these techniques to follow the small, asymptomatic, right ICA aneurysm in our patient. If the aneurysm rapidly grows or becomes symptomatic, treatment may require proximal ligation with extracranial-intracranial bypass. Understanding of the basic defects associated with EDS-Type IV will make the management of patients with vascular complications more safe.

Adult↗
PubMed1989

Occupational hydrocarbon exposure among fathers of Prader-Willi syndrome patients with and without deletions of 15q.

Prader-Willi syndrome (PWS) is a multiple-anomaly disorder in which 50%-70% of cases are associated with a de novo interstitial deletion [del 15(q11-13)] on prometaphase cytogenetic analysis, the remainder having apparently normal chromosomes. In most instances, the paternally derived chromosome has become deleted in the affected child, suggesting the possibility of a predisposing environmental factor. Strakowski and Butler found an increased incidence of paternal periconceptional employment in hydrocarbon-exposing occupations in this population. This observation may suggest a causal relationship to PWS. To determine whether this association may distinguish the cytogenetically different groups, we identified 81 patients with the disorder who were physically and cytogenetically examined in three centers, and we compared the frequency of possible periconceptional occupational hydrocarbon exposure between fathers of patients who demonstrate a 15q deletion and those who do not. There was no statistically significant difference between the cytogenetically different groups. In both groups, approximately half of the fathers had been employed in hydrocarbon-exposing jobs. These findings suggest lack of etiologic heterogeneity between the cytogenetically different groups for PWS and affirm the need to seek submicroscopic deletions through molecular genetic studies. These data also provide additional evidence that hydrocarbon exposure among fathers of children with PWS may be causally related to the disorder, and they also suggest the need for more accurate assessment of exposure via a large, controlled study.

Adolescent↗
PubMed1987

Hydrolethalus syndrome: report of an apparent mild case, literature review, and differential diagnosis.

We present an infant with manifestations of the hydrolethalus syndrome who has survived for over 5 months; previously, the longest survival reported in this condition has been 2 days. The literature is reviewed and the clinical and pathological findings of our patient are compared with those of the 50 previously reported cases. The differential diagnosis of the condition is discussed.

Abnormalities, Multiple↗
PubMed1987

Pregnancy management and successful outcome of Ehlers-Danlos syndrome type IV.

Ehlers-Danlos syndrome type IV (EDS IV) is a rare but serious disorder of connective tissue that is characterized by the abnormal production or secretion of type III collagen. Experience with pregnant patients exhibiting this syndrome is limited. This report describes the successful management of a pregnancy in a woman with EDS IV that included activity restriction and complete bed rest after 32 weeks, use of 1-desamino-8-D-arginine vasopressin (DDAVP) before delivery to improve coagulation, and cesarean section before the onset of labor. The possibility of prenatal diagnosis based on genetic linkage studies also is discussed.

Adult↗