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K N Rosenbaum

Publications and source records attributed to K N Rosenbaum.

At least 19 recordsLinked to original sources
PubMed2001

Scanning for telomeric deletions and duplications and uniparental disomy using genetic markers in 120 children with malformations.

We screened 120 children with sporadic multiple congenital anomalies and either growth or mental retardation for uniparental disomy (UPD) or subtelomeric deletions. The screening used short tandem repeat polymorphisms (STRP) from the subtelomeric regions of 41 chromosome arms. Uninformative marker results were reanalyzed by using the next available marker on that chromosome arm. In total, approximately 25,000 genotypes were generated and analyzed for this study. Subtelomeric deletions of 1 Mb in size were excluded for 27 of 40 chromosome arms. Among the 120 subjects none was found to have UPD, but five subjects (4%, 95% confidence interval 1-9%) were found to have a deletion or duplication of one or more chromosome arms. We conclude that UPD is not a frequent cause of undiagnosed multiple congenital anomaly syndrome. In addition, we determined that 9p and 7q harbor chromosome length variations in the normal population. We conclude that subtelomeric marker analysis is effective for the detection of subtelomeric duplications and deletions, although it is labor intensive. Given a detection rate that is similar to prior studies and the large workload imposed by STRPs, we conclude that STRPs are an effective, but impractical, approach to the determination of segmental aneusomy given current technology.

Abnormalities, Multiple↗
PubMed2000

Neurodevelopmental and neuroimaging correlates in nonsyndromal microcephalic children.

This descriptive study examined the relationship between head size, developmental functioning, and neuroimaging findings in children with absolute microcephaly. Subjects, aged 1 to 48 months, were assigned to one of two groups based on occipitofrontal head circumference (OFC). Group A included subjects with an OFC of 2 to 2.99 standard deviations below the mean, and Group B included subjects with an OFC of 3 or more standard deviations below the mean. Brain scan findings for 62% of the subjects were abnormal. Findings included cerebral atrophy, cortical dysplasia, myelination delay, and white matter hypoplasia. Mean scores for developmental measures in Groups A and B were less than 70. Mean developmental scores in the normal imaging group were 70 or greater, whereas developmental scores in the abnormal imaging group were 52 or less. Forty-three percent of the subjects in Group A and 80% of those in Group B had abnormal findings from imaging studies (p = .0394). Subjects with one or more brain abnormalities determined on the basis of magnetic resonance images or computed tomographic scans had significantly lower scores in all developmental areas (p < .05). The authors concluded that abnormal brain images seem to be a better reflection of developmental performance than the degree of microcephaly. J Dev Behav Pediatr 21:12-18, 2000. Index terms: microcephaly, neuroimaging, neurodevelopment.

Anthropometry↗
PubMed1998

Otologic manifestations of Wolf-Hirschhorn syndrome.

OBJECTIVE: To determine if haploinsufficiency for chromosome 4p16.3 in Wolf-Hirschhorn syndrome (WHS) is associated with cochlear hearing loss. DESIGN: Case series. SETTING: Tertiary care center. PATIENTS: Six patients with WHS were identified through a database and charts were retrospectively reviewed. MAIN OUTCOME MEASURES: Presence of sensorineural hearing loss as assessed by brainstem auditory evoked response. RESULTS: One of the 6 patients had sensorineural hearing loss. Three of the 6 patients had chronic otitis media with effusion and underwent bilateral tympanostomy tube placement; 2 of these 3 had cleft lip and palate, and 1 had a bifid uvula. One of the 6 patients had spontaneous nystagmus. Five of the 6 patients had preauricular and/or auricular abnormalities. CONCLUSIONS: More than 25 genes for nonsyndromic hereditary hearing impairment have been mapped. One of these genes, DFNA6, was identified through linkage analysis of a family with dominant, progressive, low-frequency sensorineural hearing loss. DFNA6 maps to chromosome 4p16.3, a region that is partially deleted in patients with WHS. In our series, we identified the second patient with WHS in the literature with bilateral sensorineural hearing loss. The incidence and type of otologic findings are consistent with those reported in the literature. Analysis of patients with chromosomal rearrangements represents one strategy toward identifying candidate genes for genetic hearing impairment.

Audiometry, Evoked Response↗
PubMed1997

Acampomelic campomelic dysplasia: further radiographic variations.

Acampomelic campomelic dysplasia (ACD) is a rare genetic syndrome affecting bone and connective tissue. This syndrome is a variant of the more commonly encountered campomelic dysplasia but is characterized by the absence of long bone curvature (acampomelia). Affected children have a characteristically flat facial profile and present with respiratory distress. They all have markedly hypoplastic scapulae. We present two sisters with ACD between whom there were some clinical and radiographic differences and also variations from the classic CD. We describe shallow orbits, a radiographic finding that has not been previously documented in this dysplasia.

Bone and Bones↗
PubMed1995

Neurodevelopmental profile of infants and toddlers with oculo-auriculo-vertebral spectrum and the correlation of prognosis with physical findings.

We studied the neurodevelopmental profile of infants and toddlers with oculo-auriculo-vertebral spectrum (OAV) and determined if certain physical manifestations were indicative of a poor neurodevelopmental prognosis. Twenty-four patients with OAV, aged birth to 57 months, were seen in the Department of Medical Genetics at Children's National Medical Center for multidisciplinary evaluations, including neurodevelopmental assessments. Fifty-eight percent of these children scored more than 2 standard deviations below the mean in at least one domain of development. There was no difference in developmental outcome of boys versus girls, children affected unilaterally on the right side versus left side, and those with severe clinical manifestations versus those with a milder form. Children with OAV and abnormal muscle tone had lower cognitive, gross motor, and expressive language scores (P = 0.05, P = 0.002, and P = 0.02, respectively). Those affected bilaterally had lower cognitive, fine motor, receptive language, and expressive language scores (P = 0.06, P = 0.03, P = 0.03, P = 0.02, respectively). Children with cervical spine abnormalities had lower cognitive, fine motor, and expressive language scores (P = 0.02, P = 0.04, and P = 0.04, respectively). We conclude that infants and toddlers with OAV are at increased risk for neurodevelopmental delay, especially those with abnormal muscle tone, bilateral involvement, and cervical vertebral anomalies. The complexity of the neurodevelopmental problems is strongly suggestive of central nervous system disturbances. Patients with OAV need comprehensive evaluation by a multidisciplinary team to define potential neurodevelopmental delays, allow for early intervention services, and promote an optimal developmental outcome.

Child, Preschool↗
PubMed1995

Patient with craniosynostosis and marfanoid phenotype (Shprintzen-Goldberg syndrome) and cloverleaf skull.

Marfanoid phenotype with craniosynostosis (Shprintzen-Goldberg syndrome) is a rare disorder previously described in only 5 patients. We report on the sixth known patient with this condition. The findings which distinguish our patient from others reported previously are that she was ascertained prenatally as having a cloverleaf skull; this is the first female patient described with this condition. Postnatally, she presented with arachnodactyly, camptodactyly, and clover-leaf skull. Imaging studies of the brain documented microcephaly with malformed brain, hydrocephaly, and hypoplasia of the corpus callosum. She also had choanal atresia and stenosis, a clinical finding previously reported only once, in this disorder.

Abnormalities, Multiple↗
PubMed1995

Frontometaphyseal dysplasia: neonatal radiographic diagnosis.

Frontometaphyseal dysplasia (FMD) is an uncommon genetic syndrome affecting bone and connective tissue. This condition is characterized by hyperostosis of the skull and prominence of the supraorbital ridges; long bones have flared metaphyses. Frontometaphyseal dysplasia is an X-linked dominant trait with more severe manifestations in males and with extreme variability in females. Diagnosis in the neonatal period is difficult. We present 2 newborn boys with the radiographic findings of FMD.

Abnormalities, Multiple↗
PubMed1995

Ocular findings in a family with Sotos syndrome (cerebral gigantism).

PURPOSE/METHODS: We examined the ocular features in a two-generation family with Sotos syndrome (cerebral gigantism). Sotos syndrome is characterized by excessive growth in prenatal and early life, advanced bone age, and typical facial features. RESULTS/CONCLUSION: One patient had presenile nuclear sclerotic cataracts, megalophthalmos, hypoorbitism, and exotropia. One of her daughters had megalocornea, exophoria, and iris hypoplasia. Her other daughter had megalocornea. The ophthalmologist can play an important role in the diagnosis and treatment of Sotos syndrome.

Abnormalities, Multiple↗
PubMed1994

Persistent pulmonary hypertension in newborn infants with cogenital myotonic dystrophy.

We describe two infants with congenital myotonic dystrophy that was complicated by persistent pulmonary hypertension. Both infants died of respiratory insufficiency that was unresponsive to ventilatory and pharmacologic support. One of the two infants was supported with extracorporeal membrane oxygenation before the diagnosis of congenital myotonic dystrophy was made.

Extracorporeal Membrane Oxygenation↗
PubMed1994

Variable prenatal appearance of osteogenesis imperfecta.

Osteogenesis imperfecta is a heterogeneous group of disorders of type I collagen with both lethal and nonlethal forms. Prenatal sonographic findings in affected fetuses are variable and depend on the severity of the disease. Six cases of osteogenesis imperfecta in which prenatal sonography had been performed were reviewed. Two cases of lethal type II osteogenesis imperfecta revealed short femurs at 16 to 17 weeks' gestation with development of bowing and fractures by 19 weeks' gestation. Four fetuses with the nonlethal type III or IV had femoral bowing with or without shortening in the late second or third trimester with grossly normal mineralization. Fractures in this latter group did not develop until 1 to 12 months after delivery. Understanding the progressive nature and variability of osteogenesis imperfecta is crucial in the prenatal diagnosis and management of this disease.

Adolescent↗
PubMed1993

Brachmann-de Lange syndrome with normal IQ.

The Brachmann-de Lange syndrome is a disorder with a high degree of clinical variability, generally associated with moderate to severe mental retardation. To date, 7 previous cases of Brachmann-de Lange syndrome with normal intelligence (IQ > 70) have been described. We report the eighth case of Brachmann-de Lange syndrome with normal intelligence. In reviewing the literature, consistent clinical manifestations seen in these 8 patients that are of prognostic value are the absence of significant limb anomalies and birth weight > 2,500 g.

Child, Preschool↗
PubMed1993

Mosaic 5p tetrasomy.

We report on a mildly abnormal 5-year-old girl with seizures, psychomotor retardation, and areas of hyperpigmentation who had a supernumerary marker chromosome in fibroblasts which was identified as an i(5p). To our knowledge, this is the first reported case of tetrasomy 5p. She shares in common some, but not all, manifestations of the dup (5p) syndrome. Cytogenetic analysis of relatives showed that the phenotypically apparently normal mother, maternal grandmother, and a brother of the proband also had a marker chromosome in their lymphocytes which was unrelated to the i(5p).

Abnormalities, Multiple↗
PubMed1992

New autosomal recessive syndrome of sparse hair, osteopenia, and mental retardation in Mennonite sisters.

We report on 2 Mennonite sisters with a syndrome of sparse hair, osteopenia, mental retardation, minor facial abnormalities, joint laxity, and hypotonia. Their asymptomatic consanguineous parents (inbreeding coefficient F = 1/64) have 6 other offspring, 3 of whom died in infancy of type II osteogenesis imperfecta (OI), and 3 of whom are normal. We analyzed collagens synthesized by cultured fibroblasts from these 2 sisters and their parents and detected no major abnormalities. Results of chromosomal and metabolic evaluations including amino acid analysis of plasma, urine, and hair were unremarkable. A literature search and survey of a computerized syndrome identification database did not disclose an identical phenotype. The sisters bear superficial resemblance to several known syndromes which we excluded on clinical and/or biochemical grounds. We conclude that they represent a new autosomal recessive syndrome, distinct from type II OI and perhaps unique to the Mennonite population or to this particular family.

Bone Diseases, Metabolic↗
PubMed1992

Clinical variability of type 1 neurofibromatosis: is there a neurofibromatosis-Noonan syndrome?

Detailed clinical, ophthalmological, and molecular studies were performed on a multigeneration family in which there were many subjects with type 1 neurofibromatosis, a common autosomal dominant disorder. Affected family members displayed a wide range of clinical findings including, in two subjects, features seen in Noonan syndrome (triangular facies, downward slanting palpebral fissures, micrognathia, short stature, and learning disability). Subjects have been described previously whose features have overlapped with neurofibromatosis and Noonan syndrome, and it has been suggested that these persons might represent a separate condition. DNA haplotype analysis showed linkage of the neurofibromatosis phenotype seen in this family to the proximal long arm of chromosome 17 in the region where the type 1 neurofibromatosis gene has been mapped. These results imply that the Noonan phenotype seen in some patients with type 1 neurofibromatosis might be the result of variable or variant expression of the neurofibromatosis gene on chromosome 17. The possible role of non-specific factors, such as fetal hypotonia, in producing the neurofibromatosis-Noonan phenotype needs further investigation. The availability of closely linked and intragenic molecular markers for neurofibromatosis could potentially be useful in the diagnosis and characterisation of patients and families with atypical forms of neurofibromatosis.

Adult↗
PubMed1991

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↗
PubMed1989

Bilateral absence of the ulna in twins as a manifestation of the split hand--split foot deformity.

Bilateral absence of the ulna and ulnar rays in twin female infants are described as a manifestation of the split hand--split foot deformity (ectrodactyly). Family history revealed the father had a unilateral split hand. Given the wide variability of expression of this disorder and the availability of prenatal diagnosis, there is a need for obstetricians and pediatricians to recognize parents with this malformation and appreciate the potential for severely affected offspring.

Diseases in Twins↗