Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0025362 (mental retardation)
 15,878 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This annotation has been confined to well-established clinical syndromes with recently discovered chromosomal etiologies. It deliberately omits retinoblastoma, the oft-cited paradigm of a contiguous gene syndrome, since it is usually inherited as a Mendelian single gene disorder. However, it was recognition of both the deletion of band q14 of chromosome 13 in mentally retarded children with retinoblastoma, and the linkage of retinoblastoma with the genetic marker esterase D, which resulted in the eventual cloning of the gene. Also omitted are microdeletions of the X chromosome. These disorders are seen primarily in males, who manifest the phenotypic effects of the deletion of the loci of various combinations of adjacent genes: Duchenne muscular dystrophy, glycerol kinase deficiency, adrenal hypoplasia, optic albinism, hypogonadotropic hypogonadism and anosmia (Kallman syndrome), chondrodysplasia punctata and ichthyosis. Many are also mentally retarded. The third group omitted are Mendelian disorders occurring with atypical mental retardation (not usually part of the disorder), the presumption being that they include small deletions. It is expected that other contiguous gene syndromes will be recognized eventually; Rubinstein-Taybi and Cornelia de Lange syndromes are prime candidates. Why do deletions have such dramatic consequences when a normal homologue of the region is present? If their effects were due to the uncovering of recessive genes, we would expect to see greater variations in phenotype among carriers, including normal individuals whose deletions were masked by the protective effects of dominant alleles in the homologous regions. Imprinting--the 'stamping' of a gene as it passes through the germ line--provides a more satisfactory explanation.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Old syndromes and new cytogenetics. 222 45

We experienced two cases of "Osteosclerosis" who were 12 and 15 year old sisters. Previous reported cases of this disease are 50 cases and among them only one patient was reported in Japan. Osteosclerosis seems to be inherited as an autosomal recessive trait. Parental consanguinity is also observed. The peculiar facies are evident in infancy, characterized by broad, flat nasal bridge, ocular hypertelorism and prognathic, broadened mandible. Commonly, they have cutaneous syndactylies in bilateral hands and feet, especially between the second and third finger and toe. Roentgenographically, hyperostosis with osteosclerosis can be observed in systemic bones, particularly the calvarium is greatly thickened. Since such a bony change occurs most severely at the base of the skull, important clinical symptoms of this disease are cranial nerve palsies resulting from obliterations of unilateral or bilateral several cranial nerve foramina. In many cases deafness due to progressive encroachment upon the middle ear cavities and auditory nerve canals appears early in infancy. Transient palsy of the facial nerve occurs somewhat later, and bilateral facial paralyses are usually permanent in adulthood. In some cases optic atrophy and visual field defect due to compression of the optic nerves are late complications. Other ocular symptoms are strabismus, nystagmus and exophthalmos. Anosmia and trigeminal nerve palsy are less common. Lower cranial nerve symptoms can not be noted but the reason is unclear. Chronic headache, convulsion and mental retardation are occasionally present. They are considered as a result from increased intracranial pressure due to progressive diminution of the cranial capacity. By same mechanism, several patients have died suddenly from impaction of the medulla oblongata in the foramen magnum in early adulthood. Then, some reporter puts emphasis on prophylactic opening of the foramen magnum in all adult cases.
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PMID:[Sibling case of osteosclerosis with cranial nerve symptoms]. 629 11

Among 18 NIH probands with anosmia and hypogonadotropic hypogonadism (AHH), seven had affected relatives and three had consanguineous parents. Both sexes were equally affected and parents were phenotypically normal. Parental age was not increased. Cleft lip and palate occurred in both eugonadal and hypogonadal persons, a previously reported association that may represent variable expression of AHH. Diabetes mellitus, usually insulin-dependent, was frequent in probands and their families. Other common traits included obesity, cryptorchidism, and hearing loss. All probands were chromosomally normal. The frequency of some dermatoglyphic traits of probands differed from normal, but no trait was unique to AHH. Segregation analysis of our proband sibships was consistent with a hypothesis of autosomal-recessive inheritance with variable expression. However, genetic heterogeneity was apparent when previous reports of familial AHH were surveyed. An X-linked or male sex-limited autosomal-dominant form with unilateral renal agenesis, mental retardation, and hypotelorism has been observed. The infrequent reports of direct male-to-male transmission limit characterization of an autosomal-dominant form of AHH. Our phenotypic analysis suggests that the traits of mental retardation, renal anomalies, hypotelorism, diabetes, and hearing loss may help to distinguish various forms of AHH, whereas cryptorchidism, clefts, and obesity appear in several types of families. At present, genetic counseling is dependent upon establishing inheritance pattern after examination for the known associated anomalies.
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PMID:The syndrome of anosmia with hypogonadotropic hypogonadism: a genetic study of 18 new families and a review. 688 Dec 9

We describe a large, three generation kindred in which 16 individuals were affected with alopecia, hyposmia or anosmia, conductive deafness associated with protruding ears, microtia, and/or atresia of the external auditory canal, hypogonadotropic hypogonadism due to LH/FSH deficiency, and a greater than normal tendency to dental caries. Variable manifestations include mild facial asymmetry, mental retardation, congenital heart defect, and cleft palate. This seems to be a previously undescribed pleiotropic autosomal dominant trait with variable expressivity. The manifestations can be explained on the basis of involvement of the ectoderm and neuroectoderm of the first and second branchial arches, of Rathke's pouch, and of the diencephalon.
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PMID:A newly recognized neuroectodermal syndrome of familial alopecia, anosmia, deafness, and hypogonadism. 688 Dec 16

In 1983, Johnson et al. described 16 related individuals with alopecia, anosmia or hyposmia, conductive hearing loss, microtia and/or atresia of the external auditory canal, and hypogonadotrophic hypogonadism inherited in an autosomal dominant pattern. Other less constant manifestations included facial asymmetry, mental retardation, congenital heart defect, cleft palate, and choanal stenosis. An isolated case was reported later (Johnston et al. [1987: Am J Med Genet 26: 925-927]) and thereafter an affected mother and son (Hennekam and Holtus [1993: Am J Med Genet 47: 714-716]). We describe an additional unrelated female patient with features resembling those of the previously reported cases. She presented with intrauterine growth deficiency, microcephaly, alopecia, bilateral microtia with canal atresia, conductive hearing loss, partial left facial palsy, posterior cleft palate, left choanal stenosis, tetralogy of Fallot, developmental delay, and right thumb polydactyly. Because the phenotypic abnormalities in this syndrome affect the brain, facial structures, ectoderm and its derivatives, outflow tract of the heart, and Rathke's pouch derivatives, this has suggested to previous authors etiologic involvement of the ectoderm and neuroectoderm of the first and second branchial arches, Rathke's pouch, and the diencephalon. Microtia with conductive hearing loss differentiates the condition from other ectodermal dysplasias. In the initial report, females appeared somewhat less affected than males, and there was male-to-male transmission. The mother of our patient manifests subtle features, which suggest she may be a mildly affected female. Additionally, there is a family history of early-onset alopecia in the maternal grandfather's relatives.
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PMID:Johnson-McMillin syndrome, a neuroectodermal syndrome with conductive hearing loss and microtia: report of a new case. 1283 63

Microdeletions of Xp22.3 can result in contiguous gene syndromes, showing the variable association of apparently unrelated clinical manifestations such as ichthyosis, chondrodysplasia punctata, hypogonadotropic hypogonadism, anosmia, ocular albinism, short stature and mental retardation. We report on a boy with ichthyosis, dysmorphic features and mental retardation with ADHD. The patient was born at term after a pregnancy complicated by threatened abortion; decreased fetal movements and low estriol serum levels were reported during the last trimester. The boy was referred to us at the age of 13 years. He presented with aggressive and hyperactive behavior. He had dry hair, a flat face, bilateral lens opacities, a small nose with hypoplastic tip, alae nasi and nares, a high-arched palate with a very small cleft, mixed dentition with 7 unerupted permanent teeth, left sensorineural and right mixed hearing loss with a calcified plaque of the tympanic membrane, marked shortness of terminal phalanges of hands and feet, ichthyosis of trunk and limbs. The genomic interval between AFM248th5 and KAL1 was investigated. PCR analysis showed a deletion in Xp22.3, with the distal breakpoint between the marker AFM248th5 and PABX and the proximal one between DXS278 and KAL1. Array-CGH and FISH analysis confirmed the interstitial deletion (of about 5.5 Mb) and refined the breakpoints. We discuss the phenotype of our patient in relationship to the deleted segment and the possibility of mental retardation and ADHD genes in the region.
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PMID:Contiguous gene syndrome due to an interstitial deletion in Xp22.3 in a boy with ichthyosis, chondrodysplasia punctata, mental retardation and ADHD. 1759 64

X;Y translocation is a relatively rare event in humans. Analyzed cytogenetically, the majority of these aberrations have breakpoints at Xp22 and Yq11. Females with t(X;Y)(p22;q11) are phenotypically normal except for short stature, while the males may have abnormalities. Aberrations that lead to nullisomy of the deleted region and complete loss of the respective genes have been recognized as a cause of variable contiguous gene syndromes in males. The phenotype depends on the extent and position of the deletion showing the variable association of apparently unrelated clinical manifestations such as ichthyosis, chondrodysplasia punctata, hypogonadotropic hypogonadism with anosmia, ocular albinism, short stature, and mental retardation. In addition, some patients have been reported with symptoms of attention deficit hyperactivity disorder. The extent of terminal Xp deletions is limited by the presence of male lethal genes in Xp22.2 at about 10-11 Mb from the telomere. The deletions in the majority of viable reported male patients extend to the STS ( approximately 7.0 Mb) or to the KAL1 ( approximately 8.5 Mb) loci. We present a clinical, cytogenetic, FISH, and array CGH study of a family with an Xp;Yq translocation. The chromosomal status is also discussed in the light of their phenotypic traits. The final karyotypes of the patients were designated as: Patient 1: 46,Y,der(X),t(X;Y)(p22;q12).ish der(X)(Xpter-,DXZ1+,Xqter+)mat.arr cgh Xp22.31p22.33(RP11-60P14 --> RP13-391G2)x0;arr cgh Yq11.221qter (RP11-235I1 --> RP11-270H4)x2.Patient 2: 46,X,der(X),t(X;Y)(p22;q12).ish der(X)(Xpter-,DXZ1+,Xqter+)mat.arr cgh Xp22.31p22.33(RP11-60P14 --> RP13-391G2)x1;arr cgh Yq11.221qter (RP11-235I1 --> RP11-270H4)x1.
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PMID:Familial X;Y translocation with distinct phenotypic consequences: Characterization using FISH and array CGH. 2057 56

We report the case of 3 brothers aged 34, 24, and 22 years, unmarried, who presented to our endocrinology clinic with absence of secondary sexual characters. There was no such history in other siblings, but their maternal uncle had similar complaints. On examination, all 3 had pre-pubertal appearance, voice, and genitalia along with anosmia and bimanual synkinesia. Cryptorchidism was noticed in 2 while third person had small hypoplastic testes. It was also noted that all 3 patients had icthyosis mainly involving trunk, back, and limbs. The hormonal assays were consistent with isolated hypogonadotrophic hypogonadism. IQ testing revealed mental retardation in the 2 patients. Ultrasound showed ectopic right kidney in one patient, atrophic right kidney in the second patient while the third patient had normal kidneys. MRI brain of all the patients showed poorly visualized olfactory tract and bulb. Kallmann syndrome (KS) was diagnosed based on hormonal evaluation and MRI results. Of the four types of KS: Synkinesia, renal anomaly, and X-linked pedigree pattern in our patients pointed towards X-linked type 1 KS as the possible cause. But, icthyosis and mental retardation are not usual presentation of type 1 KS. They are usually seen as a result of contiguous gene deletion of KAL1, steroid sulfatase (STS), and mental retardation (MRX) gene on X chromosome. Hence, the possible gene defect in our cases is inherited defect in contiguous gene deletion. The contiguous gene deletion as the cause of KS in 3 patients of same family is very rare and worth reporting. Also, the significance of phenotype-genotypic association in Kallmann syndrome is discussed.
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PMID:Unusual presentation of Kallmannn syndrome with contiguous gene deletion in three siblings of a family. 2356 15