Au-lait Spots (au-lait + spot)

Distribution by Scientific Domains


Selected Abstracts


Ten novel mutations in the human neurofibromatosis type 1 (NF1) gene in Italian patients

HUMAN MUTATION, Issue 1 2002
Paola Origone
Abstract The entire NF1 coding region was analyzed for mutations in a panel of 108 unrelated Italian NF1 patients. Using PTT, SSCP, and DNA sequencing, we found 10 mutations which have never been reported before. Clinical diagnosis of NF1 was established according to the NIH consensus criteria in 100 individuals, while 8 were young children with only multiple cafè-au-lait spots. We detected 46 truncated fragments, and 24 of them were fully characterized by SSCP and direct sequencing. Of the 24, 14 were known mutations (R304X, R681X, Q682X, R1306X, R1362X, R1513X, R1748X, Q1794X, R1947X, Y2264X, R2237X, 2674delA, 6789delTTAC, 2027insC). The other 10 mutations represent novel changes that contribute to the germline mutational spectrum of the NF1 gene (K810X, Q2595X, 6772delT, 7190delCT, 7331delA, 1021insTT, 3921insT, 4106insTA, 7149insC, 2033insCG / 2034delA). PTT in a large number of Italian NF1 patients supports the usefulness of this method for characterization of mutations in disorders where the responsible gene is very large and the disease-causing mutations often create a stop codon. In agreement with previous reports, no mutational hotspots within the NF1 gene were detected. © 2002 Wiley-Liss, Inc. [source]


Gs, Mutations in Fibrous Dysplasia and McCune-Albright Syndrome,

JOURNAL OF BONE AND MINERAL RESEARCH, Issue S2 2006
Lee S Weinstein
Abstract Fibrous dysplasia (FD) is a focal bone lesion composed of immature mesenchymal osteoblastic precursor cells. Some FD patients also have hyperpigmented skin lesions (café-au-lait spots), gonadotropin-independent sexual precocity, and/or other endocrine and nonendocrine manifestations (McCune-Albright syndrome [MAS]). MAS results from somatic mutations occurring during early development, resulting in a widespread mosaic of normal and mutant-bearing cells, which predicts that the clinical presentation of each patient is determined by the extent and distribution of abnormal cells. These mutations encode constitutively active forms of Gs,, the ubiquitously expressed G protein ,-subunit that couples hormone receptors to intracellular cAMP generation. These mutations lead to substitution of amino acid residues that are critical for the intrinsic GTPase activity that is normally required to deactivate the G protein. This leads to prolonged activation of Gs, and its downstream effectors even with minimal receptor activation. This explains why MAS patients have stimulation of multiple peripheral endocrine glands in the absence of circulating stimulatory pituitary hormones and increased skin pigment, which is normally induced by melanocyte-stimulating hormone through Gs,/cAMP. Similar mutations are also present in 40% of pituitary tumors in acromegaly patients and less commonly in other endocrine tumors. FD results from increased cAMP in bone marrow stromal cells, leading to increased proliferation and abnormal differentiation. Parental origin of the mutated allele may also affect the clinical presentation, because Gs, is imprinted and expressed only from the maternal allele in some tissues (e.g., pituitary somatotrophs). [source]


Impact of neurofibromatosis 1 upon quality of life in childhood: a cross-sectional study of 79 cases

BRITISH JOURNAL OF DERMATOLOGY, Issue 4 2009
P. Wolkenstein
Summary Background, Neurofibromatosis 1 (NF1) has a significant impact on quality of life (QoL). Objectives, To evaluate QoL in NF1 according to phenotype from the viewpoint of children and proxy. Methods, One hundred and forty families with a child aged between 8 and 16 years, seen consecutively at the National Academic Paediatric Referral Centre for NF1 for a phenotype evaluation, were contacted by mail. Families agreeing to participate were sent two questionnaires, the DISABKIDS for children and proxy and the cartoon version of the Children's Dermatology Life Quality Index (CDLQI). QoL scores were compared with those in other major diseases and were analysed according to age, gender and phenotype. Results, Eighty families agreed to participate, and 79 returned the questionnaires. Using DISABKIDS, NF1 had a higher impact on health-related QoL than asthma (mean ± SD 75·18 ± 18·22 vs. 79·78 ± 13·41; P = 0·005). The total score was more altered when assessed by proxy than by children (71·20 ± 17·94 vs. 75·18 ± 18·22; P = 0·002). Orthopaedic manifestations, learning disabilities and presence of at least two plexiform neurofibromas were independently associated with a higher impact (P < 0·01). The CDLQI score was slightly altered (11·3%). Dermatological signs, such as café-au-lait spots and freckling, did not have a significant impact. Conclusions, Orthopaedic manifestations, learning disabilities and plexiform neurofibromas are the main complications impacting on QoL during childhood NF1. QoL could be considered as an endpoint for intervention studies in this context. [source]


A severe form of Noonan syndrome and autosomal dominant café-au-lait spots , evidence for different genetic origins

ACTA PAEDIATRICA, Issue 4 2009
Anna-Maja Nyström
Abstract Aim: The clinical overlap among Noonan syndrome (NS), cardio-facio-cutaneous (CFC), LEOPARD and Costello syndromes as well as Neurofibromatosis type 1 is extensive, which complicates the process of diagnosis. Further genotype,phenotype correlations are required to facilitate future diagnosis of these patients. Therefore, investigations of the genetic cause of a severe phenotype in a patient with NS and the presence of multiple café-au-lait spots (CAL) spots in the patient and four members of the family were performed. Methods: Mutation analyses of candidate genes, PTPN11, NF1, SPRED1 and SPRED2, associated with these syndromes, were conducted using DNA sequencing. Results: A previously identified de novo mutation, PTPN11 F285L and an inherited NF1 R1809C substitution in the index patient were found. However, neither PTPN11 F285L, NF1 R1809C, SPRED1 nor SPRED2 segregated with CAL spots in the family. The results indicate that the familial CAL spots trait in this family is caused by a mutation in another gene, distinct from previous genes associated with CAL spots in these syndromes. Conclusion: We suggest that the atypical severe symptoms in the index patient may be caused by an additive effect on the F285L mutation in PTPN11 by another mutation, for example the NF1 R1809C or alternatively, the not yet identified gene mutation associated with CAL spots in this family. [source]


Constitutive deficiency in DNA mismatch repair

CLINICAL GENETICS, Issue 6 2007
KEA Felton
Mutations in the DNA mismatch repair (MMR) genes are associated with the inheritance of hereditary non-polyposis colorectal cancer, also known as Lynch syndrome, a cancer syndrome with an average age at onset of 44. Individuals presenting with colorectal cancer are diagnosed with Lynch I, whereas individuals who present with extra-colonic tumors (such as endometrial, stomach, etc.) are identified as patients with Lynch syndrome II. Recently, 30 families have been reported with inheritance of biallelic mutations in the MMR genes. Here we summarize the phenotype of individuals with inheritance of homozygous or compound heterozygous mutations in the MMR genes that result in a complete lack of protein or greatly compromised protein function. In contrast to individuals with Lynch syndrome I and II, individuals with no MMR function present with childhood onset of hematological and brain malignancies, whereas residual MMR function can also result in gastrointestinal cancers and an age of onset in the second to fourth decade. Individuals with biallelic MMR mutations often present with café-au-lait spots, regardless of the level of MMR function remaining. Thus, the inheritance of two MMR gene mutations is a separate entity from Lynch I or II or the subtypes Turcot and Muir,Torre. [source]