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1/8. A family with X-linked recessive fusion of metacarpals IV and V.

    We describe a family with a distinctive malformation of the hand consisting of the fusion of the 4th and the 5th metacarpal bones. Usually this anomaly is clinically recognizable by an ulnar deviation of the 5th finger; moreover, the 5th metacarpal is usually hypoplastic and the 5th ray is consequently short. There is, however, great variability in expression, so the degree of fusion may range from minimal to complete and also the external aspect of the hand may vary. This anomaly can be either isolated or part of a syndrome. For the isolated form, two possible hereditary mechanisms have been proposed: autosomal dominant and X-linked recessive. Our family is consistent with the latter, with only affected males and no instances of male-to-male transmission. Of note, there are very few X-linked recessive disorders that affect the hand in a such a specific way.
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2/8. A novel mutation in the interleukin-2 receptor gamma gene as the cause of lymphopenia in a neonate vertically exposed to human immunodeficiency virus.

    Perinatal transmission prophylaxis has led to a significant reduction of vertical human immunodeficiency virus (hiv) infection. Antiretroviral drugs are being widely used before and during pregnancy, although these drugs can have possible adverse effects on the fetus and newborn. In this context, we report a unique case of X-linked severe combined immunodeficiency in a neonate vertically exposed to hiv.
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3/8. Male-to-male transmission of X-linked Alport syndrome in a boy with a 47,XXY karyotype.

    Alport syndrome (AS) is a genetically heterogeneous renal hereditary disease. Male-to-male transmission has been considered fully indicative of autosomal dominant AS. We report a family with male-to-male transmission of X-linked AS due to an extra X chromosome of paternal origin in the proband. Linkage analysis excluded the autosomal loci and demonstrated segregation with the COL4A5 locus (Xq22.3). Sperm FISH analysis from his father detected an increased XY disomy. Mutation screening of the COL4A5 gene identified a splicing mutation, c.4688G>A. The proband and his paternal grandmother showed random x chromosome inactivation. However, a preferential expression of the aberrantly spliced transcript was detected in the proband when compared to his grandmother. This finding could explain why the AS phenotype of this 47,XXY boy resembles more an affected male than a female carrier. This is the first reported case of concurrence of Alport and Klinefelter syndromes.
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4/8. Importance of genetic diagnosis of DAX-1 deficiency: example from a large, multigenerational family.

    BACKGROUND: Inactivating mutations of DAX-1 give rise to the X-linked form of adrenal hypoplasia congenita (AHC). Affected fetuses are at risk of early postnatal Addisonian crisis, but the variable phenotypic expression of DAX-1 insufficiency renders this diagnosis challenging. methods: We describe the familial transmission of AHC over several generations. The proband was diagnosed with adrenal insufficiency at age 3.5 years: molecular analysis revealed a novel, 373-bp deletion including the second exon of DAX-1. Given the familial history of several unexplained deaths in male infants related to the proband via his maternal great-grandmother, we hypothesized that all these boys had been affected with AHC. Another female member of the family being pregnant with a male fetus at the time, we performed DAX-1 analysis on the mother and the newborn. The mother was heterozygous for the deletion, and the newborn hemizygous: he presented an adrenal crisis at 10 days of life, and is now doing well on hormone replacement therapy. CONCLUSION: The unfortunate deaths of male infants at each generation of this family underlie the importance of early and precise diagnosis of this rare condition, stressing the value of genetic diagnosis in six potential female carriers of this family entering their reproductive years.
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5/8. Tissue-specific distribution of an alternatively spliced COL4A5 isoform and non-random x chromosome inactivation reflect phenotypic variation in heterozygous X-linked Alport syndrome.

    A novel type of hereditary transmission of COL4A5 in a Japanese family with X-linked Alport syndrome was detected through analysis of cDNA sequences and an X-chromosome inactivation assay. A female patient with moderately altered renal function, who was diagnosed with Alport syndrome by renal biopsy, and her mother, who was undergoing maintenance haemodialysis, showed similar tissue-specific expression of a truncated isoform of COL4A5, which was generated by alternative splicing without a splice-site mutation. Expression of the truncated isoform occurred in the renal specimen derived from the patient, but not in specimens from controls. Genomic analysis revealed two point mutations (c.4821 121, T>C; c.4822-151_150, ins T) in intron 49 of COL4A5 from the patient. The peripheral blood mononuclear cells of the patient and her mother showed non-random lyonization. While the females showed only renal impairment, an affected male in the same family suffered from severe renal insufficiency, visual defect and hearing disturbances. Hence, we suggest that this type of heredity COL4A5 presents with phenotypic variation in female heterozygous X-linked Alport syndrome patients.
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6/8. child syndrome in 3 generations: the importance of mild or minimal skin lesions.

    BACKGROUND: child syndrome (congenital hemidysplasia with ichthyosiform nevus and limb defects, Online Mendelian Inheritance in Man 308050) is an X-linked dominant trait with lethality for male embryos. The disorder is caused by mutations in NSDHL (Online Mendelian Inheritance in Man 300275), a gene playing an important role in the cholesterol biosynthetic pathway. Most reports deal with sporadic cases, and only 5 cases of mother-to-daughter transmission have been documented. We present here a family with mild features of child syndrome in 3 generations. Molecular analysis was used to confirm the diagnosis. OBSERVATIONS: We studied 14 members of a family with child syndrome. The 23-year-old proposita, her mother, 2 aunts, and her grandmother presented with mild or minimal skin lesions that had been present since infancy. Analysis of the NSDHL gene showed missense mutation c.370G-->A in these 5 patients. This mutation was absent in the 9 clinically unaffected family members tested. CONCLUSIONS: In this family, we recognized child syndrome with mild or minimal features in 3 generations because we were able to verify our clinical diagnosis by means of molecular analysis. We assume that many cases that so far have been considered sporadic may in fact be familial when a meticulous physical examination of female family members is combined with molecular testing.
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7/8. Bilateral periventricular heterotopias in an X-linked dominant transmission in a family with two affected males.

    We report on the case of dizygotic twin boys, born prematurely to an asymptomatic mother. Bilateral periventricular heterotopias with enlarged ventricles were discovered at birth in both twins. One of the twins died prematurely of bronchopulmonary complications, and was shown to have several neuropathological anomalies (microgyria, thin corpus callosum, and reduced white matter). The surviving twin had mental retardation, without epilepsy. MRI of the mother showed asymptomatic periventricular heterotopias without ventricular enlargement. She had two affected daughters also with asymptomatic periventricular heterotopias. A point mutation in the last coding exon 48 of the Filamin A (FLNA) gene (7922c > t) was discovered on sequencing and segregated with the affected individuals. This family has a classical X-linked dominant BPNH pathology, with greater severity in males than females. The location of the FLNA mutation is discussed in light of the neuropathological anomalies and mental retardation in male patients.
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8/8. Three cousins with chronic foot ulcers from late-onset hereditary sensory and autonomic neuropathies type 2 (HSAN2).

    The hereditary sensory and autonomic neuropathies (HSAN) are a group of rare disorders characterized by prominent sensory and autonomic neuropathy without motor involvement. We report three male cousins with chronic foot ulcers, all were affected with late-onset HSAN type 2 (HSAN2). In view of the history of consanguinity and male sex, X-linked recessive transmission was likely in our patients. According to the authors' knowledge this is the first report of HSAN2 from iran.
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