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21/131. Postmortem findings in the coffin-lowry syndrome.

    The coffin-lowry syndrome (CLS) is a congenital disorder that can be recognized by retarded growth and development, the characteristic appearance of the face and hands, and often by the typical deformities of the back and chest; there are many other anomalies. The history of the syndrome is reviewed, noting the x-linked semidominant pattern of inheritance, and two autopsies are presented and compared with the three autopsy reports that have been published previously. The five young patients died at ages between 18 to 28 years of advancing pneumonia, aspiration of food into the trachea, or postoperative complications. There were lesions or abnormalities in the heart, brain, lungs, liver, skeleton, kidneys, intestines, and other organs. Molecular geneticists have located the CLS gene or Rsk-2 gene at Xp22.2 and demonstrated that it works by influencing the activation of other genes. The "monopolygenic" pattern may help to explain the large number of seemingly unrelated abnormalities that make up this syndrome. ( info)

22/131. Analysis of RPGR in a South African family with X-linked retinitis pigmentosa: research and diagnostic implications.

    Analysis of exon ORF15 of the RPGR gene has revealed a novel mutation in a South African family with X-linked retinitis pigmentosa (XLRP), which has implications for the rest of the family in terms of pre-symptomatic testing. The ability to test for this mutation will be beneficial for the accurate determination of carrier status in female relatives who may have been unaware of their risk before this study was performed. This work also highlights the need to be aware of the ramifications of mutation testing in what may appear to be small families. This is the first report of an RPGR ORF15 mutation in a South African family of mixed ancestry. ( info)

23/131. X-linked myotubular myopathy in a family with three adult survivors.

    We describe a family with an extremely mild form of X-linked myotubular myopathy. Three affected males survived to adulthood with sufficient muscle strength to enable them to carry out normal daily activities. The mildness of the myopathy in this family is highlighted by the following: no neonatal or infant mortality resulting from the myopathy; one affected male who did not have neonatal asphyxia and had normal early motor milestones - this affected male was able to increase his muscle bulk and strength to normal by weightlifting; and a 55-year-old male who still lives an independent life. dna sequencing identified a novel missense mutation - G469A (E157K) - in exon 7 of the MTM1 gene in this family. To our knowledge, this is the third X-linked myotubular myopathy family, with multiple adult survivors, to be reported in the literature. ( info)

24/131. X-linked centronuclear myopathy.

    We report the cases of two male preterm newborns with X-linked centronuclear myopathy (CNM). This is the most severe type of CNM. Each of them presented with generalized hypotonia, weakness, difficulty in swallowing, and respiratory distress at birth. physical examination of both newborns revealed long thin face, high-arched palate, mild bilateral ptosis, frog-leg posture, and absence of deep tendon reflex. diagnosis of the disease was made according to fetal history, family history, muscle histopathology, electron microscopy, and genetic analysis. Subdural hemorrhage of brain and subcapsular hematoma of the liver were found at autopsy of Case 1. The results of molecular analysis of Case 2 and his family favored the diagnosis of X-linked CNM. Molecular studies can be easily performed with only minute amount of dna of patients, and may help the clinician to predict which patients may be at the risk for medical complications. ( info)

25/131. McLeod syndrome resulting from a novel XK mutation.

    McLeod Syndrome (MLS) is a rare X-linked disorder characterized by haemopoietic abnormalities and late-onset neurological and muscular defects. The McLeod blood group phenotype is typically associated with erythrocyte acanthocytosis, absence of the Kx antigen and reduced expression of Kell system antigens. MLS is caused by hemizygosity for mutations in the XK gene. We describe a patient with MLS who first showed symptoms in 1989 (aged 51 years). As the disease progressed, the patient developed a slight dementia, aggressive behaviour and choreatic movements. A cardiomyopathy was also diagnosed. An electroneuromyography showed neuropathic and myopathic changes. liver enzymes were elevated and a blood smear showed acanthocytes. MLS was confirmed by serological analysis of the Kell antigens. Analysis of red blood cells by flow cytometry revealed the patient and his grandson to have reduced Kell antigen expression. The patient's daughters had two populations of red cells, consistent with them being heterozygous for an XK0 allele. The molecular basis of MLS in this family is a novel mutation consisting of a 7453-bp deletion that includes exon 2 of the XK gene. This confirms that the patient's 7-year-old grandson, who is currently asymptomatic, also has the XK0 allele and is therefore likely to develop MLS. ( info)

26/131. A frameshift mutation of the ED1 gene in sibling cases with X-linked hypohidrotic ectodermal dysplasia.

    X-linked hypohidrotic ectodermal dysplasia (XLHED; MIM 305100) is characterized by the absence or hypoplasia of hair, teeth, and sweat glands. The ED1 gene was identified as a responsive gene for XLHED. The patients were 2 Japanese brothers. Both had the same mutation in exon 1 of the ED1 gene, i.e. C deletion at nucleotide 49, which induced a frameshift starting from amino acid 17 and made a stop codon at amino acid 56, encoding the transmembrane site. The mutation caused the extracellular domain of ectodysplasin A to be completely absent. Their mother had a heterozygous allele; she congenitally lacked 1 tooth, and incisors appeared conical in form. ( info)

27/131. Unusual manifestations in X-linked amelogenesis imperfecta.

    This paper describes a female with X-linked amelogenesis imperfecta (XAI). This case is unusual in having taurodontism, pulpal calcifications, coronal defects prior to tooth eruption and unerupted teeth. These findings have been reported in some cases of autosomal dominant and autosomal recessive AI but have not previously been documented in XAI. ( info)

28/131. Complete recovery from cryptosporidium parvum infection with gastroenteritis and sclerosing cholangitis after successful bone marrow transplantation in two brothers with X-linked hyper-IgM syndrome.

    We describe two brothers who suffered from hyper-IgM syndrome (HIGM1) with similar clinical features: recurrent infections, especially cryptosporidium gastroenteritis with cholangitis. Their activated T cells did not express CD40L. Nucleotide sequencing revealed a mutation in both boys with respect to intron 4 and exon 5 boundaries of the CD40L gene in Xq26. They underwent successful bone marrow transplantation (BMT) from HLA-geno-identical siblings. The Cryptosporidium infection and cholangitis resolved thereafter. At 6 months after BMT, expression of CD40L on activated T lymphocytes was normal. After 1 year, both boys are well, and immune reconstitution has improved. Based on these two successful experiences, BMT with a genoidentical sibling seems a reasonable therapeutic approach for HIGM1, if Cryptosporidium infection occurs. ( info)

29/131. X-linked cubitus valgus with mental retardation and typical face.

    In 1973, Jones and Smith described two maternal male first cousins with a similar pattern of malformation, including mental retardation, cubitus valgus, and unusual facies. The purpose of this report is to describe three additional cases, a 10-year-old male and his 30-year-old maternal uncle and an unrelated 15-year-old boy, bringing to five the total number of individuals with this disorder. The principal features include moderate mental retardation, mild microcephaly, a short philtrum, deep-set, downslanting palpebral fissures, multiple nevi, and striking cubitus valgus. documentation of this disorder in two maternal male first cousins as well as in a male and his maternal uncle support an X-linked recessive mode of inheritance for this condition. ( info)

30/131. A new X-linked syndrome with agenesis of the corpus callosum, mental retardation, coloboma, micrognathia, and a mutation in the Alpha 4 gene at Xq13.

    We describe two brothers with a unique pattern of malformations that includes coloboma (iris, optic nerve), high forehead, severe retrognathia, mental retardation, and agenesis of the corpus callosum (ACC). Both boys have low-set cupped ears with sensorineural hearing loss, normal phallus, pectus excavatum, scoliosis, and short stature. One brother had choanal atresia and cardiac defects consisting of ventricular septal defect (VSD) and patent ductus arteriosus (PDA) which resolved spontaneously. Differential diagnosis between a number of clinical entities was considered, however, because ACC and the distinctive facial features were reminiscent of FG syndrome, dna was analyzed for markers linked to the FGS1 locus at Xq13-q21. Notably, the brothers were concordant for markers spanning this presumed FG region, and in both we have identified adjacent alterations (-57delT and T-55A) in the Alpha 4 gene located within this interval. Alpha 4 is a regulatory subunit of the major cellular phosphatase, PP2A, that has recently been shown to interact with MID1, the product of the gene mutated in X-linked Opitz GBBB syndrome. The double nucleotide change identified in this family was not observed in 410 control chromosomes, suggesting that it may be a pathogenetic change. Altered expression of Alpha 4, through either a change in translational efficiency, mRNA stability or splicing, could explain the clinical phenotype in these boys and the phenotypic overlap with Opitz GBBB syndrome. ( info)
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