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X-linked hypogonadism, gynecomastia, mental retardation, short stature, and obesity--a new syndrome.

Five male members in four generations of the same family had hypogonadism, gynecomastia, mental retardation, obesity, and short stature. The X-linked mode of inheritance, the distinctive facies, the normal size of the hands and feet, and the true gynecomastia are the main characteristics. Endocrine evaluation and histologic studies of the testes suggest partial hypogonadotropic hypogonadism. This disorder represents a new syndrome distinct from others previously described.

Adult↗

A biologic and genetic study of 40 cases of severe pure mental retardation.

The family history of 40 patients with severe "pure" mental retardation (MR) was studied to determine the incidence of mental retardation and dull-normal intelligence among relatives, probable etiologies and an empiric recurrence risk. Significant findings include: (1) an increased sex ratio (69% males) of propositi, (2) a significant proportion of patients with clinical manifestations besides MR, (3) virtually no consanguinity among parents, (4) a "positive" family history for over 1/2 of the propositi--about 37% of all children in the sibships were affected; about 21% of the full sibs were affected, (5) a higher number of offspring produced by dull persons and a lower number of offspring from retarded persons compared to two normal persons (6) a proportionately large number of affected children produced from matings involving one or two dull persons, (7) a tendency for dull to have additional dull children and mentally retarded parents to have further retarded children while normal parents with more than one affected child usually had further retarded children, (8) an incidence of affected parents of about 32%, and (9) an overall empiric recurrence risk of 14%. Several etiologies were discussed as possible causes of the condition(s) in this group: (unrecongized) environmental damage and/or maternal/fetal interaction; unrecognized chromosome abnormalities; the homozygous state of several different autosomal recessive gees: X-linked recessive mutations; autosomal dominat new mutations; and mutifactoral inheritance. It was concluded that the group was etiologically heterogeneous and although none of the probable etiologies could be excluded, it seemed reasonable to assume that autosomal recessive inheritance plays an important role in the etiology of severe "pure" mental retardation.

Adolescent↗

A presumptive new variant of Norrie's disease.

The present report describes a Brazilian Negro sibship with six males affected by a presumptive new variant of Norrie's disease, an X-linked congenital oculo-acoustical-cerebral degeneration. In addition to the typical stigmata of the disease, all the patients were microcephalic and two of them had cryptorchidism. Possible non-genetic aetiology was investigated with negative results. Xg blood group studies were informative and the lod scores are given, together with those for two previously reported families with Norrie's disease.

Adolescent↗

An etiological survey of the severely retarded Hertfordshire children who were born between January 1, 1965 and December 31, 1967.

An etiological survey is presented of all suveryl retarded children living in Hertfordshire, at home and in residential care, born between January 1, 1965, and December 31, 1967. One hundred and forty-six children (87 boys and 59 girls) were ascertained, out of a total population of 46,960, with a prevalence of 1 in 320 or 3.1 per 1,000. Approximately 1/3 (47) had the Down syndrome, 1 per 1,000 population. It was possible to establish a diagnosis in a further 45 cases, which included 1 additional case of autosomal chromosome abnormality and 7 each of autosomal dominant, recessive and X-linked conditions; 17 were associated with presumed multifactorial etiological factors; in 6 the condition was thought to have been caused by an environmental agent. It was not possible to establish a cause in the remaining 54 cases. Recurrence risks of severe mental retardation in cases where it is possible to establish a definite diagnosis are discussed and the potential value, for genetic counseling purposes, of a categorizing such patients into broad symptomatological groups, is suggested.

Dermatoglyphics↗

The X-linked syndrome of macroorchidism and mental retardation: further observations.

We report six males with the syndrome of macroorchidism and mental retardation. The trait is inherited as though X-linked, or possibly autosomal dominant male-limited. We also found no evidence of gonadal dysfunction. Associated abnormalities were abnormal EEG (3/4), seizures (2/6), and one instance each of cervical vertebral fusion, cataract, esophoria, and abnormal cutaneous pigmentation. One woman with a 50% a priori risk of bearing the mutant gene had mental retardation and seizures. Results of Xg blood-group typing were uninformative for the purpose of linkage analysis.

Abnormalities, Multiple↗

The FG syndrome: further characterization, report of a third family, and of a sporadic case.

We report 5 new cases of the FG syndrome, 1 sporadic, 3 brothers from a European family, and another affected male born in the first FG syndrome family reported by Opitz and Kaveggia in 1974. The pedigree data confirm the hypothesis of X-linked inheritance of this multiple congenital anomaly/mental retardation (MCA/MR) syndrome. Its manifestations include shortness of stature with a disproportionately large head, mental retardation, hypotonia with or without congenital joint contractures, seizures and a strikingly characteristic personality of facial appearance, imperforate anus and/or orthe gastrointestinal defects, congenital heart defects, and many minor manifestations. Chronic pulmonary disease in some affected males may be a complication of hypotonia.

Abnormalities, Multiple↗

Heritable fragile sites on human chromosomes. III. Detection of fra(X)(q27) in males with X-linked mental retardation and in their female relatives.

The fragile site at Xq27 which is associated with X-linked retardation with macroorchidism has been studied in 21 retarded males. These males were from 12 families, and studies of nine of the familes were possible. Detection of carrier females is difficult, especially with increasing age. The fragile site was demonstrated in only five of 13 obligate carrier females. It is concluded that using present methods, cytogenetic detection of carriers is fairly reliable in females aged less than 20--25 years but unreliable in older females.

Adolescent↗

Reliability of Békésy threshold tracing in identification of carriers of genes for an X-linked disease with deafness.

Seven identified carriers and 20 potential carriers of Norris's disease have been examined by pure tone octave audiometry and Békésy audiometry. The investigation supports earlier results of Békésy threshold tracings performed in heterozygote carriers of genes for recessive hearing impairment. The sensitivity of the method is poor. The specificity of the Békésy threshold tracing is high, meaning that an absent dip cannot exclude the possibility of a subject being a carrier, whereas a present dip can be regarded as an indication of carrier. When comparing conventional octave audiometry and Békésy threshold tracing, the latter method is found to be more subtle in finding carriers of genes for recessive deafness. Therefore, Békésy threshold tracing may be of help in the genetic counselling of potential carriers of genes for recessive deafness.

Adolescent↗

A study of possible heterogeneity in Duchenne muscular dystrophy.

One possible explanation for the apparently high birth incidence of Duchenne muscular dystrophy (DMD), a lethal X-linked disorder, is genetic heterogeneity. As a first step in possibly demonstrating genetic heterogeneity, affected boys were sub-divided into those with and without severe mental handicap. In those with severe mental handicap, ages at onset and of becoming confined to a wheelchair were later, the fall in SCK level with age was less marked, and the urinary excretion of certain aminoacids was greater than in affected boys with normal intelligence. Though the number of subjects investigated was relatively small (15 in each group) and further studies are therefore needed, the results suggest that DMD may not be a single disease entity.

Adolescent↗

Norrie disease is caused by mutations in an extracellular protein resembling C-terminal globular domain of mucins.

A candidate gene for Norrie disease, an X-linked disorder characterized by blindness, deafness and mental disturbances, was recently isolated and found to contain microdeletions in numerous patients. No strong homologies were identified. By studying the number and spacing of cysteine residues, we now detect homologies between the Norrie gene product and a C-terminal domain which is common to a group of proteins including mucins. Three newly-characterized missense mutations, replacing evolutionarily conserved cysteines or creating new cysteine codons, emphasize the functional importance of these sites. These findings and the clinical features of this disorder suggest a possible role for the Norrie gene in neuroectodermal cell-cell interaction.

Adult↗

Familial Kallmann syndrome with unilateral renal aplasia.

On the basis of studies in two brothers and their double first cousin, the Kallmann syndrome (KS) is discussed as an X-linked syndrome of anosmic hypogonadotropic hypogonadism. The anosmia is thought to represent agenesis or hypoplasia of the olfactory lobes, the mildest form of the alobar holoprosencephaly developmental field defect; this is supported by the finding of hypotelorism in two of the patients and their mother. The endocrine defect is thought to represent a hypothalamic abnormality of the luteinizing hormone releasing hormone; borderline normal intelligence may represent another pleio-tropic CNS manifestation of the KS gene. All three affected males had unilateral renal aplasia, associated in one with ipsilateral absence of the testis. The presence of at least two developmental field defects (involving the CNS and urogenital system) makes it likely that the KS is a true multiple congenital anomaly syndrome; this is supported by the finding of additional, mostly minor, anomalies reported by other investigators. Heterozygous females may also show manifestations of anosmia, hypogonadism, possibly even internal genital malformation; however, genetic heterogeneity of anosmic hypogonadism is possible, and for the time being it is probably better to designate sporadic female cases of anosmic hypogonadism as examples of the olfacto-genital syndrome of DeMorsier. Linkage studies are urgently needed to clear up the question of genetic heterogeneity and to help develop empiric recurrence risk figures in anosmic hypogonadism.

Adult↗

X-linked mental retardation with macro-orchidism and marker X chromosomes.

A family with X-linked mental retardation and a marker X chromosome was ascertained by the presence of macro-orchidism in the three institutionalized probands. Verbal evaluation revealed a generalized language disability with commonly occurring articulation errors. The heterozygous females in this family exhibited some reduction in mental ability; the marker X chromosome was demonstrated in both sexes.

Female↗

X-linked dysosteosclerosis. Four familial cases.

Four Spanish children with clinical and radiological features corresponding to dysosteosclerosis are presented. All the children were male and belonged to the same family. The first known carrier is the maternal grandmother, who had three daughters by three different fathers who in turn had one or more sons with the disease. The four carriers were normal. Consanguinity did not occur in any case and the disorder was transmitted as a sex-linked recessive condition.

Adolescent↗

The Norrie disease gene maps to a 150 kb region on chromosome Xp11.3.

Norrie disease is a human X-linked recessive disorder of unknown etiology characterized by congenital blindness, sensory neural deafness and mental retardation. This disease gene was previously linked to the DXS7 (L1.28) locus and the MAO genes in band Xp11.3. We report here fine physical mapping of the obligate region containing the Norrie disease gene (NDP) defined by a recombination and by the smallest submicroscopic chromosomal deletion associated with Norrie disease identified to date. Analysis, using in addition two overlapping YAC clones from this region, allowed orientation of the MAOA and MAOB genes in a 5'-3'-3'-5' configuration. A recombination event between a (GT)n polymorphism in intron 2 of the MAOB gene and the NDP locus, in a family previously reported to have a recombination between DXS7 and NDP, delineates a flanking marker telomeric to this disease gene. An anonymous DNA probe, dc12, present in one of the YACs and in a patient with a submicroscopic deletion which includes MAOA and MAOB but not L1.28, serves as a flanking marker centromeric to the disease gene. An Alu-PCR fragment from the right arm of the MAO YAC (YMAO.AluR) is not deleted in this patient and also delineates the centromeric extent of the obligate disease region. The apparent order of these loci is telomere ... DXS7-MAOA-MAOB-NDP-dc12-YMAO.AluR ... centromere. Together these data define the obligate region containing the NDP gene to a chromosomal segment less than 150 kb.

Base Sequence↗

Fragile sites on human chromosomes: demonstration of their dependence on the type of tissue culture medium.

The observation of heritable fragile sites on human chromosomes prepared for lymphocyte cultures has been shown to depend on the type of tissue culture medium in which the lymphocytes are grown. The sites are observed at a much greater frequency when medium 199 is used than when RPMI 1640, Ham's F10, Eagle's (basal), and CMRL 1969 are used. One site on the X chromosome is of clinical significance in that it is a marker for X-linked mental retardation.

Cells, Cultured↗

X-linked hydrocephalus, with aqueductal stenosis, mental retardation, and adduction-flexion deformity of the thumbs. Report of a family.

A new family is reported of a Bickers-Adams-Edwards syndrome. This family has been studied up to three generations. Two female carriers are known. Among the six male children who are affected, four are severely mentally retarded, have spasticity of the legs, and survived with a mild macrocephaly, and two show a more severe and rapid progression of head enlargement. A partial aqueductal stenosis, with remarkable ventricular dilatation, has been demonstrated by pneumoence-phalography in three boys. A deformity of the thumbs links these six children together. One of them has been treated by a ventriculoperitoneal shunt, when 18 months old, without any improvement in the neurological condition. The mental deficiency is much more severe than could be expected from the degree of hydrocephalus, at least as estimated clinically by the macrocephaly. Hydrocephalus is precocious, and the ventricular dilatation very advanced when seen by PEG studies. Recognition of the female carriers is not possible.

Adolescent↗

X-linked recessively inherited non-specific mental retardation. Report of a large family.

A large kindred is described in which 22 males and 3 females show non-specific mental retardation with impaired speech. An X-linked recessive is the most likely mode of inheritance of this condition. Similar families have been described in the literature, characteristic physical abnormalities are absent and performance I.Q. tends to be higher than verbal I.Q. This possible heterogenous condition may be a major individual cause of mental deficiency in males, and may account for the excess of male retardates in the population.

Adolescent↗

Familial X-linked mental retardation, verbal disability, and marker X chromosomes.

Cytogenetic and verbal studies were done on members of four families with non-specific X-linked mental retardation. Cytogenetic analysis was done using media 199 and GTG-banding; one family had a marker X with a fragile site in band Xq27 or 28. Preliminary results indicate variation of culture conditions can effect the frequency of the marker X. A generalized language disability was found which tended to concentrate in the areas of auditory reception, auditory sequential memory, visual closure and grammatic closure. Articulation errors involved the same sounds which are late in normal development and occur most frequently in both the general population and a Down syndrome population.

Chromosome Banding↗