A new autosomal recessive disorder resembling Weaver syndrome

Most reported cases of Weaver syndrome are sporadic, and the mode of inheritance is still unclear. We describe two (male and female) sibs born to consanguineous Bedouin parents with manifestations resembling Weaver syndrome. Both sibs had accelerated growth of prenatal onset, hypotonia, psychomotor retardation, excess loose skin, peculiar craniofacial and acral anomalies, dental dysplasia and/or serrated gums, joint laxity, and hoarse low-pitched cry. One of them had an accelerated harmonic skeletal maturation. Differentiating features from Weaver syndrome are discussed, and autosomal recessive inheritance is suggested.     

A 90 kb DNA deletion associated with neurofibromatosis type 1.

A deletion of 90 kb of DNA has been identified in a patient with neurofibromatosis type 1, using pulsed field gel electrophoresis. The deletion lies between probes 17L1A and AC5 in the critical region of chromosome 17 and represents the only molecular alteration found by PFGE in a series of 90 unrelated patients. The subject showing the deletion is an isolated case, shows typical clinical features, and represents one of the first examples of a molecular deletion to be found in this disorder.     

Diffuse ganglioneuromatosis in small intestine associated with neurofibromatosis type 1

Ganglioneuromatosis of the gastrointestinal tract is a rare condition that has an established association with the multiple endocrine neoplasia syndrome, type IIb. Its occurrence in neurofibromatosis, in which the large intestine is usually affected, is much rarer. We report a case of diffuse ganglioneuromatosis of the small bowel, found incidentally during surgery for a malignant peripheral nerve sheath tumor arising in the retroperitoneum in a 32-year-old man with neurofibromatosis type 1, and review previously reported cases.     

Familial café au lait spots: a variant of neurofibromatosis type 1.

Café au lait spots (CALS) are a frequent and one of the early manifestations of neurofibromatosis 1 (NF1). However, there are patients with isolated CALS who do not meet the diagnostic criteria for NFI. There are several reports of families in which CALS are inherited as an autosomal dominant trait, without any other features of NFI. In one reported family with dominantly inherited CALS linkage to the NF1 locus was ruled out. In order to elucidate the relationship between familial CALS and NF1 further, we performed a linkage analysis in a large kindred with 11 subjects with CALS in three generations and established close linkage between CALS and five NF1 intragenic polymorphisms. We propose that in this family the trait of CALS is allelic to NF1, it is fully penetrant, and it does not confer a risk of other NF1 symptoms.     

Emotional functioning among children with neurofibromatosis type 1 or Noonan syndrome

While neurofibromatosis type 1 (NF1) and Noonan syndrome (NS) are clinically distinct genetic syndromes, they have overlapping features because they are caused by pathogenic variants in genes encoding molecules within the Ras‐mitogen‐activated protein kinase signaling pathway. Increased risk for emotional and behavioral challenges has been reported in both children and adults with these syndromes. The current study examined parent‐report and self‐report measures of emotional functioning among children with NF1 and NS as compared to their unaffected siblings. Parents and children with NS (n = 39), NF1 (n = 39), and their siblings without a genetic condition (n = 32) completed well‐validated clinical symptom rating scales. Results from parent questionnaires indicated greater symptomatology on scales measuring internalizing behaviors and symptoms of attention deficit hyperactivity disorder (ADHD) in both syndrome groups as compared with unaffected children. Frequency and severity of emotional and behavioral symptoms were remarkably similar across the two clinical groups. Symptoms of depression and anxiety were higher in children who were also rated as meeting symptom criteria for ADHD. While self‐report ratings by children generally correlated with parent ratings, symptom severity was less pronounced. Among unaffected siblings, parent ratings indicated higher than expected levels of anxiety. Study findings may assist with guiding family‐based interventions to address emotional challenges.     

A girl with the Weaver syndrome.

A female with the Weaver syndrome is reported. In addition to the characteristic manifestations of overgrowth and advanced bone age, the facies were typical, with a broad forehead, hypertelorism, a long philtrum, micrognathia, and large ears. Like most other patients with Weaver syndrome, she was developmentally delayed, hypertonic, and had a hoarse voice. Other clinical features included prominent finger pads, narrow hyperconvex nails, small and narrow chest, unilateral dislocated distal ulna, and abnormal thoracic vertebrae.     

Epidemiology of neurofibromatosis type 1.

The prevalence of neurofibromatosis type 1 (NF1) is about 1/3,000. There are no known ethnic groups in which NF1 does not occur or is unusually common. The prevalence is somewhat higher in young children than in adults, a difference that probably results at least in part from the early death of some NF1 patients. NF1 is fully penetrant in adults, but many disease features increase in frequency or severity with age. The reproductive fitness of NF1 patients is reduced by about one-half. About half of all cases result from new mutations. The estimated rate of new NF1 mutations is unusually high, but the basis for this high mutation rate is not known. Am. J. Med. Genet. (Semin. Med. Genet.) 89:1-6, 1999.     

Absence of linkage of Noonan syndrome to the neurofibromatosis type 1 locus.

Eleven families with Noonan syndrome in either two or three generations have been identified. Following the reports of subjects with features of both Noonan syndrome and neurofibromatosis type 1, these pedigrees have been studied using a number of probes at the neurofibromatosis type 1 locus (17q11). A significantly negative lod score was obtained with the intragenic probe NF1-C2, suggesting that the genes for Noonan syndrome and neurofibromatosis type 1 are not contiguous.     

Cognitive impairment in neurofibromatosis type 1.

Neurofibromatosis type 1 (NF1) is associated with a broad range of relatively nonspecific cognitive impairments, including low IQ, learning disabilities, and behavioral difficulties. While early studies indicated that the cognitive phenotype of NF1 resembles that of nonverbal learning disabilities (NLD), later research has found that the impairments are broader and do not fit the NLD profile well. Language-based deficits and executive dysfunction have also been found in empirical studies. There is some evidence that neuropsychological impairment may be correlated with the underlying central nervous system involvement of NF1, but this theory has not been consistently supported across studies. Further work clarifying the cognitive phenotype of NF1 is needed, especially investigations that employ appropriate comparison groups matched for intellectual level. Am. J. Med. Genet. (Semin. Med. Genet.) 89:45-52, 1999.     

Intracranial gliomas in neurofibromatosis type 1.

Optic pathway gliomas and brainstem gliomas are the predominant intracranial neoplasms associated with neurofibromatosis type 1 (NF1). Before the past 15 years, studies of optic pathway gliomas in NF1 were hampered by the inaccurate diagnosis of NF1, the unavailability of noninvasive neuroimaging techniques, and the frequent rendering of what would now be considered unnecessary, overly aggressive therapy. When studied systematically, these tumors behave in a much more benign fashion than their counterparts in children who do not have NF1. While they may cause symptoms in as many of 50% of cases, progression to the point where specific intervention is deemed necessary is unusual. Consequently, screening neuroimaging of asymptomatic patients is unwarranted. Because optic pathway tumors universally arise in children younger than 7 years of age, all such children should undergo yearly ophthalmologic evaluations and annual assessments of growth to monitor for signs of precocious puberty. Am. J. Med. Genet. (Semin. Med. Genet.) 89:38-44, 1999.     

Carcinosarcoma of the lung associated with neurofibromatosis type 1: a case report

Neurofibromatosis or von Recklinghausen's disease is the most common inherited syndrome predisposing to neoplasia. Carcinosarcoma is a rare malignant mixed tumor of the lung. Association of carcinosarcoma of lung with Neurofibromatosis-1 is not common. A 57-year-old man presented with history of fever, cough, hemoptysis, breathlessness, weight loss, chest pain. Multiple cutaneous neurofibromas and café au lait spots were revealed by physical examination. A homogeneous opacity was found in the right middle and right upper zone on posterior-anterior chest radiography. A 8x8x7 cm mass that had irregular borders in right upper posterior and apical segment was seen on contrast enhanced chest computed tomography. On bronchoscopy, the lumen of right upper apical segment was obstructed with vegetating tumoral lesion. The biopsy taken from this region was diagnosed as carcinosarcoma by histopathological and immunohistochemical examination.A rare case with carcinosarcoma of the lung and Neurofibromatosis-1 was reported.     

Weaver syndrome with pes cavus

Few cases have been described of the Weaver syndrome, an overgrowth syndrome with advanced skeletal age. Here we report bilateral pes cavus in an affected girl.     

Revised diagnostic criteria for neurofibromatosis type 1 and Legius syndrome: an international consensus recommendation

PurposeBy incorporating major developments in genetics, ophthalmology, dermatology, and neuroimaging, to revise the diagnostic criteria for neurofibromatosis type 1 (NF1) and to establish diagnostic criteria for Legius syndrome (LGSS).MethodsWe used a multistep process, beginning with a Delphi method involving global experts and subsequently involving non-NF experts, patients, and foundations/patient advocacy groups.ResultsWe reached consensus on the minimal clinical and genetic criteria for diagnosing and differentiating NF1 and LGSS, which have phenotypic overlap in young patients with pigmentary findings. Criteria for the mosaic forms of these conditions are also recommended.ConclusionThe revised criteria for NF1 incorporate new clinical features and genetic testing, whereas the criteria for LGSS were created to differentiate the two conditions. It is likely that continued refinement of these new criteria will be necessary as investigators (1) study the diagnostic properties of the revised criteria, (2) reconsider criteria not included in this process, and (3) identify new clinical and other features of these conditions. For this reason, we propose an initiative to update periodically the diagnostic criteria for NF1 and LGSS.

1. Download : Download high-res image (128KB)
2. Download : Download full-size image