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S J Hayflick

Publications and source records attributed to S J Hayflick.

25 records · Page 2Linked to original sources

Clouston syndrome (hidrotic ectodermal dysplasia) is not linked to keratin gene clusters on chromosomes 12 and 17.

Clouston syndrome is an hidrotic form of ectodermal dysplasia, inherited as an autosomal dominant trait with high penetrance. The main features of the disorder are alopecia, severe dystrophy of the nails, and palmoplantar hyperkeratosis. A molecular abnormality of keratin has long been hypothesized to be the basic defect in this disorder. We have performed linkage analyses between the disorder and markers close to the keratin gene clusters on chromosomes 12 and 17 and have excluded linkage to these candidate regions in three apparently unrelated families. In addition, linkage has been excluded to four other candidate regions including 1q2l, 17q23-qter, 18q2l, and 2Oql2. These data indicate that Clouston syndrome is not due to a defect in keratin or in a subset of keratin-associated proteins.

Chromosome Mapping↗

Cobalamin C defect associated with hemolytic-uremic syndrome.

We describe a female infant with typical features of the cobalamin C form of combined methylmalonic aciduria and homocystinuria who also had the hemolytic-uremic syndrome with thrombocytopenia, microangiopathic hemolytic anemia, hypertension, and renal failure. Review of this and other described cases of the cobalamin C defect suggests that the hemolytic-uremic syndrome is part of the phenotypic spectrum of this inborn error of cobalamin metabolism.

Female↗

Chromosomal deletion 4p15.32----p14 in a Treacher Collins syndrome patient: exclusion of the disease locus from and mapping of anonymous DNA sequences to this region.

Treacher Collins syndrome is an autosomal dominant condition of bilateral craniofacial abnormalities of structures derived from the first and second branchial arches. A patient with severe manifestations of Treacher Collins syndrome and a de novo chromosomal deletion in region 4p15.32----p14 was identified. Anonymous DNA sequences of loci D4S18, D4S19, D4S20, D4S22, and D4S23 were mapped to the deleted region. DNA probes previously mapped to loci on chromosome 4p (D4S10, D4S15, D4S16, D4S26, D4S35, D4S95, D4S144, RAF1P1, QDPR, and HOX7) were not deleted in this patient. Linkage analysis between the D4S18, D4S23, and QDPR loci and Treacher Collins syndrome in eight families excluded the Treacher Collins syndrome locus from the region of the deletion.

Chromosome Deletion↗

Neurofibromatosis 1: recognition and management of associated neuroblastoma.

Neurofibroma and neuroblastoma both arise from the neural crest, and there has long been speculation regarding a pathogenetic relationship between them. Clinical characteristics do not necessarily distinguish these tumors, therefore the diagnosis of neuroblastoma should be considered in all children with neurofibromatosis 1 (NF-1) who have a rapidly growing or inaccessible mass. A careful physical examination, imaging studies, and urinary catecholamine measurement are indicated. In a child with NF-1 and malignancy, direct tissue examination may be necessary to differentiate malignant from nonmalignant tumor and guide therapy. Furthermore, with the significantly increased risk of certain types of childhood cancer in these patients, we recommend evaluation for this common heritable condition in all patients with malignancy.

Catecholamines↗

Primary care physicians' utilization and perceptions of genetics services.

PURPOSE: To document primary care physicians' utilization and perceptions of genetics services. METHODS: A randomized survey of physicians in the Pacific Northwest. RESULTS: The greatest factor prompting a genetics referral was the patient's interest in the evaluation, and the most common reason not to obtain a consultation was the perception that it was of no benefit to the patient. Genetics consultation was rarely sought for a family history of cancer or for deafness, polycystic kidney disease, or congenital heart disease. Even when uncertain about relative risk, physicians usually counseled a patient themselves rather than referring to a specialist. CONCLUSION: Primary care physicians need more education about the genetic component of many diseases to provide directly and to refer appropriately for genetics services.

Attitude of Health Personnel↗

Brain MRI in neurodegeneration with brain iron accumulation with and without PANK2 mutations.

BACKGROUND AND OBJECTIVE: Patients with a clinical diagnosis of neurodegeneration with brain iron accumulation (NBIA, formerly called Hallervorden-Spatz syndrome) often have mutations in PANK2, the gene encoding pantothenate kinase 2. We investigated correlations between brain MR imaging changes, mutation status, and clinical disease features. METHODS: Brain MRIs from patients with NBIA were reviewed by 2 neuroradiologists for technical factors, including signal intensity abnormalities in specific brain regions, presence and location of atrophy, presence of white matter abnormality, contrast enhancement, and other comments. PANK2 genotyping was performed by polymerase chain reaction amplification of patient genomic DNA followed by automated nucleotide sequencing. RESULTS: Sixty-six MR imaging examinations from 49 NBIA patients were analyzed, including those from 29 patients with mutations in PANK2. All patients with mutations had the specific pattern of globus pallidus central hyperintensity with surrounding hypointensity on T2-weighted images, known as the eye-of-the-tiger sign. This sign was not seen in any studies from patients without mutations. Even before the globus pallidus hypointensity developed, patients with mutations could be distinguished by the presence of isolated globus pallidus hyperintensity on T2-weighted images. Radiographic evidence for iron deposition in the substantia nigra was absent early in disease associated with PANK2 mutations. MR imaging abnormalities outside the globus pallidus, including cerebral or cerebellar atrophy, were more common and more severe in mutation-negative patients. No specific MR imaging changes could be distinguished among the mutation-negative patients. CONCLUSION: MR imaging signal intensity abnormalities in the globus pallidus can distinguish patients with mutations in PANK2 from those lacking a mutation, even in the early stages of disease.

Adolescent↗