Parent-of-origin in individuals with familial neurofibromatosis type 1 and optic pathway gliomas.

Neurofibromatosis type 1 (NF1) is one of the most common autosomal dominant cancer syndromes worldwide. Individuals with NF1 have a wide variety of clinical features including a strongly increased risk for pediatric brain tumors. The etiology of pediatric brain tumor development in NF1 is largely unknown. Recent studies have highlighted the contribution of parent-of-origin effects to tumorigenesis in sporadic cancers and cancer predisposition syndromes; however, there is limited data on this effect for cancers arising in NF1. To increase our understanding of brain tumor development in NF1, we conducted a multi-center retrospective chart review of 240 individuals with familial NF1 who were diagnosed with a pediatric brain tumor (optic pathway glioma; OPG) to determine whether a parent-of-origin effect exists overall or by the patient's sex. Overall, 50 % of individuals with familial NF1 and an OPG inherited the NF1 gene from their mother. Similarly, by sex, both males and females were as likely to inherit the NF1 gene from their mother as from their father, with 52 % and 48 % of females and males with OPGs inheriting the NF1 gene from their mother. In conclusion, in contrast to findings from other studies of sporadic cancers and cancer predisposition syndromes, our results indicate no parent-of-origin effect overall or by patient sex for OPGs in NF1.

Genotype-phenotype correlations in Rubinstein-Taybi syndrome.

Rubinstein-Taybi syndrome (RTS) is a rare multiple congenital anomaly/intellectual impairment syndrome. Loss of function in CREBBP or EP300 genes has been found in about 50% of patients with RTS. Genotype-phenotype correlations were investigated in 93 patients meeting diagnostic criteria for RTS during 2 international RTS family conferences. Mutation analysis of CREBBP was performed on all 31 coding exons and exon-intron junctions; a subset of patients had FISH analysis for large deletions. A total of 64 different variations were observed in the DNA sequence, and determined to be definitive mutations in 52 patients (56%). Mutations detected included: 10 missense mutations; 36 truncating or splice-site mutations; and 6 large deletions detectable by FISH. Fourteen patients had synonymous changes of unknown significance. The majority of mutations affected the HAT domain of CREBBP or predicted termination of the protein before the HAT region. Extensive phenotypic data were collected on each patient and analyzed to determine correlations with mutation types, that is, truncating, large deletions, single amino acid substitutions, or no CREBBP mutation. All four groups displayed the characteristic facial and thumb dysmorphology. Growth retardation in height and weight was seen more frequently in patients with no CREBBP mutation; seizure disorder was more frequent in those with CREBBP mutations. Degree of mental retardation was similar in all groups, although there was a trend toward lower IQ and autistic features in patients with large deletions. Similarity in phenotype between the groups implies that the several genes involved in causing RTS likely have effects through the same pathway.

Skeletal demineralization and fractures caused by fetal magnesium toxicity.

Two surviving female infants, born from a triplet pregnancy at 30 weeks gestation, were noted to have severe osteopenia and multiple fractures diagnosed at 20 days of age. Their mother had been treated for preterm labor with intravenous magnesium sulfate from week 22 until their birth at 30 weeks gestation. At birth, the triplets exhibited craniotabes with enlarged fontanelles and sutures. All developed Respiratory Distress Syndrome (RDS) and the two surviving infants required prolonged respiratory support. Serum calcium and phosphate levels were normal and alkaline phosphatase levels were increased. The infants were treated with supplements of calcium and phosphorous, with resultant healing of the multiple fractures without deformity. Fetal magnesium toxicity impairs bone mineralization and can lead to serious bone demineralization that may cause fractures in the newborn period that complicate recovery from respiratory disease. Early recognition and treatment may minimize complications related to osteopenia caused by fetal magnesium toxicity.

Increased need for medical interventions in infants with velocardiofacial (deletion 22q11) syndrome.

Ten of 12 patients diagnosed with deletion 22q11.2 in infancy required a total of 26 hospitalizations during their first year of life. After heart disease, feeding and respiratory problems were the most frequent reasons for intervention.

Neurofibromatosis in children: the role of the orthopaedist.

Type 1 neurofibromatosis (NF-1), also known as von Recklinghausen disease, is one of the most common human single-gene disorders, affecting at least 1 million persons throughout the world. It encompasses a spectrum of multifaceted disorders and may present with a wide range of clinical manifestations, including abnormalities of the skin, nervous tissue, bones, and soft tissues. The condition can be conclusively diagnosed when two of seven criteria established by the National Institutes of Health Consensus Development Conference are met. Most children with NF-1 have no major orthopaedic problems. For those with musculoskeletal involvement, the most important issue is early recognition. Spinal deformity, congenital tibial dysplasia (congenital bowing and pseudarthrosis), and disorders of excessive bone and soft-tissue growth are the three types of musculoskeletal manifestations that require evaluation. Statistics gathered from the Cincinnati Children's Hospital Neurofibromatosis Center database show the incidence of spinal deformity in children with NF-1 to be 23.6%; pectus deformity, 4.3%; limb-length inequality, 7.1%; congenital tibial dysplasia, 5.7%; hemihypertrophy, 1.4%; and plexiform neurofibromas, 25%. The orthopaedic complications can be managed, but only rarely are they cured.

Descriptive analysis of tibial pseudarthrosis in patients with neurofibromatosis 1.

Five percent of individuals with neurofibromatosis type 1 (NF1) present with congenital long bone pseudarthrosis (PA). In large series, 50-80% of patients with congenital long bone PA also have NF1. Very little information exists on the natural history and pathogenesis of PA in NF1. This report is a descriptive analysis of a large series of patients with NF1 and tibial bowing or PA. Study A is a case-control study using the National Neurofibromatosis Foundation International Database (NNFFID). Eighty-five patients with PA were compared to a control group from the same database. There was a statistically significant male predominance of NF1 cases with PA (54 males to 31 females), compared to controls (85 males to 87 females) (chi2 = 4.0, P = 0.046, using a two-tailed test with Yates' correction). There was no significant difference in the clinical presentation of NF1 manifestations in NF1 patients with PA than in NF1 patients without PA. Of the affected individuals with PA, there were 24 de novo cases and 21 familial cases (9 through maternal and 12 through paternal inheritance). Questions that could not be answered by Study A were addressed by a partially overlapping case-series report, Study B, in which data on 75 cases ascertained through questionnaires completed by NF center directors were collected. From Study B we determined that half of the patients who had a fracture sustained it before age 2, and approximately 16% of the pseudarthrosis patients had an amputation. Our data indicate a male predominance and no parent-of-origin effect. Male gender may be a susceptibility factor for pseudarthrosis in NF1.

Social and emotional problems in children with neurofibromatosis type 1: evidence and proposed interventions.

OBJECTIVE: To describe social and emotional problems in children and adolescents with neurofibromatosis type 1 (NF1) and propose interventions. Our hypothesis is that children with NF1 will have significantly more social and emotional problems, compared with their unaffected siblings and children in the general population. STUDY DESIGN: Forty-three children with NF1 and 22 unaffected siblings (ages 5 to 18 years) were assessed with a standardized test completed by parents and teachers (the Child Behavior Checklist). RESULTS: As with other aspects of NF1, there was variable expressivity. However, when rated by parents, children with NF1 had significantly more problems in comparison with test norms or unaffected siblings on 7 of 8 scales: Social Problems, Attention Problems, Anxiety/Depression, Withdrawal, Thought Problems, Somatic Complaints, and Aggressive Behavior. Children with NF1 also scored lower than unaffected siblings on measures assessing sports and other activities. Teachers reported fewer differences. CONCLUSIONS: We propose interventions in the form of information for parents; early screening and treatment for speech, motor, and cognitive problems; and an increased level of intervention to prevent and treat psychologic problems, including systematic screening with standardized tests.

Partial trisomy 1q with growth hormone deficiency and normal intelligence.

We present two sibs with partial trisomy 1 (q31.1-q32.1) due to a familial insertion. Patient 1 is a girl who presented at age 9 months with minor anomalies, short stature, and normal psychomotor development. Karyotype was 46,XX,der(4)ins(4;1) (p14;q31.1q32.1)pat. The father had a balanced inverted insertion of 1q into 4p, with karyotype 46,XY,ins(4;1)(p14;q31.1q32.1). At age 5 years, patient 1 was found to have short stature with documented growth hormone deficiency and ectopic pituitary. Her growth velocity responded well to treatment with growth hormone. Cognitive testing at 5 9/12 years showed normal intelligence with an IQ of 90. Patient 2, the brother of patient 1, presented with intrauterine growth retardation. He has the same chromosomal insertion as his sister, with partial trisomy 1q. We suggest that there is a recognizable phenotype of trisomy 1(q31.1-q32.1) which includes prenatal and postnatal growth retardation, narrow palpebral fissures, microphthalmia, microstomia, pituitary abnormalities, and normal intelligence in some individuals.

Thoracic tumors in children with neurofibromatosis-1.

Thoracic tumors have been infrequently reported as a complication of neurofibromatosis-1 (NF1). To determine the prevalence and clinical features of thoracic tumors seen in children with NF1, we reviewed medical records and imaging studies for a group of 260 pediatric patients with NF1 followed in a multidisciplinary NF Center. Extrapleural thoracic tumors were seen in nine patients with NF1, corresponding to a prevalence of 3.5% in this hospital-based series of patients. Pathological studies of the tumors demonstrated plexiform neurofibroma in four cases and neurofibrosarcoma in one case. The remaining four cases were suspected to be plexiform neurofibroma based on clinical features but have not been confirmed histologically. Three patients presented with symptoms of chest pain, syncope, or wheezing; six patients were asymptomatic at the time of diagnosis of the tumors. Physical findings frequently found in patients with thoracic tumors were scoliosis (especially focal scoliosis) and visible plexiform neurofibromas of the neck. We conclude that NF1 patients presenting with any of these signs and symptoms should be screened for thoracic tumors with chest X-ray and magnetic resonance imaging as needed. It is unknown whether screening asymptomatic NF1 patients with chest X-rays on a regular basis will result in an improved outcome.

Ullrich-Turner syndrome and neurofibromatosis-1.

There is a well-known association between neurofibromatosis-1 (NF1) and Noonan syndrome-like manifestations, including short stature, short broad neck, and hypertelorism. These anomalies are thought to be due to variable expression of the NF1 gene. We report on two girls with NF1 who were found to have the Ullrich-Turner syndrome. Case 1, a 12-year-old white girl, was followed in a Neurofibromatosis Clinic because of multiple café-au-lait spots and a family history of NF1 in her mother and sister. On examination, she had short stature, hypertelorism, and short neck with low posterior hairline. Karyotype was 86% 46,XY/14% 45,X. Case 2, the first child of a woman with NF1, presented at birth with lymphedema of hands and feet and a short broad neck. Karyotype was 45,X. At age 23 months she was short, had epicanthic folds, hypertelorism, narrow palate, right simian crease, 19 café-au-lait spots, and axillary freckling. We conclude that chromosome studies should be performed in girls with NF1 who have short stature and Noonan- or Ullrich-Turner-like findings. Dilemmas raised by the dual diagnoses of NF1 and Ullrich-Turner syndrome include potential risks of growth hormone therapy and estrogen replacement therapy.

Familial partial duplication (1)(p21p31).

A partial duplication (1)(p21p31), resulting from a maternal direct insertion (13,1) (q22p21p31), was found in a 30-year-old woman with mental retardation, cleft palate, and multiple minor anomalies. Two other affected and deceased relatives were presumed to have the same chromosome imbalance. Duplication 1p cases are reviewed.

A refined genetic map of the region of chromosome 17 surrounding the von Recklinghausen neurofibromatosis (NF1) gene.

The von Recklinghausen neurofibromatosis (NF1) gene has been mapped to the pericentromeric region of chromosome 17. We conducted linkage analyses of NF1 by using 10 polymorphic DNA markers from this chromosomal region. We ascertained 20 American Caucasian NF1 families (163 individuals, 98 NF1 affected) in Michigan and Ohio and also studied a large family ascertained primarily in North Carolina. The following markers were used in this study: HHH202, TH17.19, D17Z1, ERBA1, EW203, EW206, EW207, EW301, CRI-L581, and CRI-L946. NF1 did not recombine with either TH17.19 or HHH202 in any of the informative meioses surveyed (maximum lod scores of 17.04 and 7.21, respectively, at a recombination fraction of .00), indicating that these markers map very close to the NF1 gene. We also report evidence of three instances of recombination between NF1 and the centromeric marker D17Z1 (maximum lod score of 13.43 at a recombination fraction of .04), as well as two crossovers between pairs of marker loci. We find no evidence of locus heterogeneity, and our results support the localization of the NF1 gene to proximal chromosome 17q.

Summary of patient data from a multidisciplinary neurofibromatosis clinic.

The Neurofibromatosis Clinic of the Children's Hospital Medical Center in Cincinnati, Ohio, is a multidisciplinary clinic which provides comprehensive care for persons affected with neurofibromatosis. Data are presented on 78 patients who fulfill the diagnostic criteria for neurofibromatosis-1. The information reported includes patient characteristics, complications and testing results.