Pre- and postnatal growth retardation--severe mental retardation--acral limb deficiencies with poorly keratinized nails. Another example of a distinct syndrome of inherited intrauterine dwarfism?

In this report, we further delineate an autosomal recessive syndrome with prenatal growth retardation, severe postnatal growth failure, profound mental and motor retardation, characteristic face and acral limb deficiencies with poorly keratinized nails and hypoplastic distal phalanges.     

Two female siblings with a previously unreported MCA/MR syndrome: pre- and postnatal growth retardation, iris colobomata, spasticity, facial dysmorphism and dilated ventricles.

We report two siblings from non consanguineous parents with a similar MCA/MR syndrome: Pre- and postnatal growth retardation, microcephaly, mental retardation, iris colobomata, facial dysmorphism, spasticity, dilated ventricles and abnormal immunoglobulin levels. Review of published reports and the use of the London Dysmorphology Database suggests that these siblings may present a new syndrome.     

Microencephalic nanism, severe retardation, hypertonia, obesity, and hypogonadism in two brothers: a new syndrome?

Two brothers are described with a severe syndrome of postnatal growth and mental retardation which includes extreme microcephaly, obesity developing during infancy, microgonadismsm, and a characteristic amphora-shaped facies. The neurological exam is highly abnormal, with hypertonia and hyperreflexia, nystagmus, and an extremely irritable and agitated behavior. The first child, who died at 4/1/2 years, also presented neonatal hypoglycemia and chronic constipation. Although the etiology of this syndrome is unknown, it is tempting to consider an X-linked recessive gene, given the importance of the X chromosome in mental retardation. Among the over 70 syndromes of X-linked mental retardation already described, our patients resemble individuals with the B?rjeson-Forssman-Lehmann (BFL) syndrome the most. However, the severity of their dwarfism and mental retardation is much greater than described in any BFL patient to date, and the neurological and dysmorphic features vary significantly from those described in the BFL. Although a particularly severe variant, perhaps allelic, is a possibility, an as yet undescribed disorder is also plausible, the etiology of which would probably be recessive, either autosomal or X-linked.     

Kabuki syndrome and trisomy 10p

Kabuki syndrome (KS) (MIM 147920) is a multiple congenital anomalies/mental retardation syndrome of unknown cause. There is multisystem involvement of anomalies, including 1) unique facial features, 2) postnatal growth retardation, 3) mild-to-moderate mental retardation, 4) skeletal anomalies and 5) dermatoglyphic abnormalities. Kabuki syndrome remains a clinical diagnosis despite significant research on detection of the genetic cause. We present 10 patients with Kabuki syndrome with a brief overview of the syndrome. An additional male patient and his affected aunt, both with trisomy 10p due to unbalanced segregation of a familial translocation, are also discussed for overlapping features and differential clinical diagnosis of the two conditions. Considering a significant overlap in clinical pictures of Kabuki syndrome and trisomy 10p in these two patients, as well as the previous patients with chromosomal abnormalities, we conclude that chromosome analysis is an important step in clinical work-up of patients with Kabuki syndrome.     

MCA/MR syndrome with severe pre- and postnatal growth retardation, deep mental retardation, distinct facial appearance with nasal hypoplasia, cleft palate and retino-choroidal coloboma in two unrelated female patients

We describe the clinical findings and natural history in two unrelated deeply mentally retarded females, now 28 and 20 years old respectively. Both presented prenatal growth retardation and severe postnatal growth retardation. Their craniofacial appearance is distinct with nasal hypoplasia, triangular mouth and thin lips. Both have a cleft palate and a retinal coloboma at the right eye. Motor development is below the age of 1 year with a complex neurological syndrome with axial hypotonia and spastic quadriplegia.     

Ring chromosome 14 syndrome. Report of two cases, including extended evaluation of a previously reported patient and review.

A case of r(14) chromosome is described and new information is added to a previously reported patient. The r(14) syndrome is reviewed on the basis of 37 known patients. The major features include prenatal and postnatal growth retardation, mental retardation, seizures, microcephaly, and distinct facial dysmorphism, including elongated face, narrow palpebral fissures, epicanthus, and broad nasal bridge. Other characteristic anomalies found only in some patients are retinal anomalies, lymphoedema of hands and feet, and prones to pulmonary infections.     

Distal duplication 14q: Report of three cases and further delineation of the syndrome

Summary Three cases of distal duplication 14q are presented. The first two cases are cousins in a kindred segregating a balanced translocation t(14;18)(q31;q23). The third case resulted from a maternal translocation t(14;18)(q24;p11). By review of these cases and those previously reported, a distal duplication 14q syndrome is further delineated. Common features include postnatal growth retardation, mental retardation, hypotonia, microcephaly, slanted palpebral fissures, ocular hypertelorism, sparse eyelashes and eyebrows, nasal dysmorphism, tented lip, micrognathia, posteriorly rotated ears, and minor skeletal anomalies.     

A new case of neonatal progeroid syndrome with agenesis of corpus callosum

We report on a female infant with a history of severe intrauterine and postnatal growth retardation, pseudohydrocephaloid cranium, frontal bossing, widened fontanelles, prominent scalp veins, progeroid face, entropion, beaked nose, small mouth, generalized lipodystrophy, camptodactyly and hypoplasia of lower limb muscles, suggesting the diagnosis of neonatal progeroid syndrome (NPS). In addition, she had congenital hip dysplasia and agenesis of corpus callosum. It is the first Hungarian case with neonatal progeroid syndrome.     

Age- and region-specific imbalances of basal amino acids and monoamine metabolism in limbic regions of female Fmr1 knock-out mice

The Fragile X syndrome, a common form of mental retardation in humans, originates from the loss of expression of the Fragile X mental retardation gene leading to the absence of the encoded Fragile X mental retardation protein 1 (FMRP). A broad pattern of morphological and behavioral abnormalities is well described for affected humans as well as Fmr1 knock-out mice, a transgenic animal model for the human Fragile X syndrome. In the present study, we examined neurochemical differences between female Fmr1 knock-out and wildtype mice with particular focus on neurotransmission. Significant age- and region-specific differences of basal tissue neurotransmitter and metabolite levels measured by high performance liquid chromatography were found. Those differences were more numerous in juvenile animals (postnatal day (PND) 28-31) compared to adults (postnatal day 209-221). In juvenile female knock-out mice, especially aspartate and taurine were increased in cortical regions, striatum, cerebellum, and brainstem. Furthermore, compared to the wildtype animals, the juvenile knock-out mice displayed an increased level of neuronal inhibition in the hippocampus and brainstem reflected by decreased ratios of (aspartate + glutamate)/(taurine + GABA), as well as an increased dopamine (DA) turnover in cortical regions, striatum, and hippocampus. These results provide the first evidence that the lack of FMRP expression in female Fmr1 knock-out mice is accompanied by age-dependent, region-specific alterations in brain amino acids, and monoamine turnover, which might be related to the reported synaptical and behavioural alterations in these animals.     

Early growth determines longevity in male rats and may be related to telomere shortening in the kidney

Maternal protein undernutrition can influence the growth and longevity of male offspring in the rat. We tested the hypothesis that these differences in longevity were associated with changes in the rate of telomere shortening. We found age-related shortening of telomeres in the liver and kidney but not in the brain of male rats. Growth retardation in postnatal life was associated with significantly longer kidney telomeres and an increased longevity. Conversely, growth retardation during the foetal life followed by postnatal catch-up growth was associated with a shorter life span and shorter kidney telomeres. These findings may provide a mechanistic basis for epidemiological studies linking early growth retardation to adult degenerative diseases.     

Patterns of psycholinguistic development in the severely mentally retarded: A hypothesis

Abstract

We hypothesize that the loss of psycholinguistic skills in some cases of severe mental retardation caused by prenatal disruption closely approximates ontogenetic patterns of language acquisition and phylogenetic patterns of cognitive development. This hypothesis was tested on 131 trainable mental retardates divided into four etiological classes. The results support the hypothesis and show that certain patterns of loss occur only in mental retardation resulting from prenatal disruption and characterized by postnatal developmental delay and do not occur in postnatal environmentally caused retardation.     

Cryptic translocation t(5;18) in familial mental retardation

A cryptic translocation t(5;18)(qter;qter) was detected in a large family, using a FISH-based approach combining subtelomeric probes to allow the subtelomeric regions of most chromosome ends to be analysed for deletions and balanced or unbalanced translocations. Unbalanced karyotypes (duplication 5qter/deficiency 18qter) resulted in a previously undescribed association of moderate to severe mental retardation, microcephaly, pre- and postnatal growth retardation, distinct facial dysmorphism, narrow auditory canals, genital hypoplasia, left heart hypoplasia in one patient and severe behaviour difficulties in another. Some of the features observed in affected individuals are characteristic of known syndromes involving either 18q (growth deficiency, nystagmus, narrow auditory canals, genital hypoplasia, behaviour problems in 18q deletion syndrome) or 5q (umbilical and inguinal hernias, congenital heart defects in distal 5q trisomy).     

Characterization of genomic variants in CSH1 and GH2, two candidate genes for Silver-Russell syndrome in 17q24-q25

Silver-Russell syndrome (SRS) is a syndrome of severe pre- and postnatal growth retardation and typical dysmorphic features. Rare chromosomal aberrations have been reported in SRS; among these are two balanced translocations involving 17q24-q25. Recently, we described a patient with a paternally inherited heterozygous deletion of the chorionic somatomammotropin hormone 1 (CSH1) gene. The CSH1 gene is member of the growth hormone (GH) gene cluster on 17q, which consists of two growth hormone genes and three CSH genes. Genomic alterations in the GH cluster are well known, causing different phenotypes depending on the size of the deletion and the genes involved. By screening 63 SRS cases with marker D17S254, we have detected 2 further patients with a heterozygous deletion in the GH cluster. Quantitative analysis using restriction assays confirmed these findings. Additionally, in a cohort of 17 patients with isolated intrauterine and postnatal growth retardation, we detected a further patient to be carrier of a CSH1 deletion. Screening of 141 unrelated controls revealed hemizygosity in one person for which data on growth were not available. We additionally analyzed our cohort of SRS patients for mutations in CSH1 and its 3' neighbour GH2. However, analyses failed to reveal any pathogenic mutation. While the central role of GH1 in human growth is well established, the physiological roles of CSH1 and other components of the cluster are unclear. The increased prevalence of hemizygosity of CSH1 in our population in comparison to controls indicates a role for CSH1 haploinsufficiency in the etiology of growth retardation. Investigation of CSH1 deletions in further SRS and growth retarded patients will enable us to establish under which circumstances haploinsufficiency of CSH1 is likely to result in clinical changes.     

Prenatal diagnosis of mitochondrial DNA8993 T----G disease.

We have previously described a family with a neurological syndrome comprising neurogenic muscle weakness, ataxia, retinitis pigmentosa, and variable sensory neuropathy, seizures, and mental retardation or dementia. This is associated with a heteroplasmic point mutation of mtDNA at bp 8993. The mother of a severely affected child underwent prenatal diagnosis in two further pregnancies. Analysis of chorionic villus samples showed a higher proportion of mutant mtDNA on both occasions, and this was reflected in the majority of fetal tissues, including brain and muscle. Prenatal diagnosis is a rational approach to the prevention of severe diseases caused by point mutations of mtDNA but is currently hampered by incomplete knowledge concerning the proportion of mutant mtDNA: its relationship to disease severity, how it may change during fetal and postnatal development, and its tissue distribution.     

Developing ways of reducing allograft immunogenicity.

Heavy alcohol consumption by the mother during pregnancy has long been suspected of being a risk factor for abnormalities in the fetus or infant. Only during the last decade have these assumptions been supported by scientific studies. A clustering of fetal defects observed in some cases has been labelled the fetal alcohol syndrome. The syndrome involves prenatal and postnatal growth retardation, central nervous system involvement and craniofacial abnormalities, some of which are characteristic of the syndrome. Fetal alcohol syndrome is relatively rare, affecting from 1 in 300 to 1 in 2000 infants; approximately 450 cases have been reported since the syndrome was identified. Despite this rarity, however, heavy alcohol consumption is an important risk factor during pregnancy. A review of the current literature indicates that in animals alcohol in high doses is embryotoxic and teratogenic, the heavy drinking is not uncommon before and during pregnancy and that the fetal alcohol syndrome and other effects on the fetus associated with alcohol abuse appear with significant frequency among mothers who drink heavily. Heavy alcohol consumption is a perinatal risk factor that not only can be detected by the physician, but also can be reduced in concerned, cooperative patients. Thus, awareness of this problem gives health care personnel an opportunity to help in the prevention of abnormal outcomes of pregnancy.     

Behavioural and developmental abnormalities in mouse trisomy 19: an animal model of mental retardation induced by chromosome imbalance

Murine trisomy 19 (Ts19) can be regarded as a general model of human trisomies. It is the only autosomal trisomy in the mouse that survives the perinatal period. Therefore, it is the only animal model available for postnatal investigations of trisomy-specific mental retardation. To evaluate the extent of developmental retardation during the late-embryonic and fetal period of gestation, total body weight development was documented for 60 Ts19-fetuses and compared with that of 219 euploid in utero-mates. In addition, a postnatal study on body-weight development of 77 Ts19-neonates and 74 euploid littermates was performed starting on day 1 postpartum and continuing until spontaneous death or until day 22. Forty-seven Ts19-individuals were further tested in nine behavioural test systems in order to determine their neurophysiological developmental profile. Findings were compared with age-dependent morphologic and physiologic parameters. The data obtained in the present study show a significant retardation of organ- and body-weight development in Ts19-mice starting on day 14 of gestation. Retardation of physiological parameters is progressive and persists throughout the perinatal and postnatal periods. Furthermore, the trisomic individuals showed specific behavioural abnormalities.     

Deletion of the MBII-85 snoRNA gene cluster in mice results in postnatal growth retardation

Prader-Willi syndrome (PWS [MIM 176270]) is a neurogenetic disorder characterized by decreased fetal activity, muscular hypotonia, failure to thrive, short stature, obesity, mental retardation, and hypogonadotropic hypogonadism. It is caused by the loss of function of one or more imprinted, paternally expressed genes on the proximal long arm of chromosome 15. Several potential PWS mouse models involving the orthologous region on chromosome 7C exist. Based on the analysis of deletions in the mouse and gene expression in PWS patients with chromosomal translocations, a critical region (PWScr) for neonatal lethality, failure to thrive, and growth retardation was narrowed to the locus containing a cluster of neuronally expressed MBII-85 small nucleolar RNA (snoRNA) genes. Here, we report the deletion of PWScr. Mice carrying the maternally inherited allele (PWScr^m−/p+) are indistinguishable from wild-type littermates. All those with the paternally inherited allele (PWScr^m+/p−) consistently display postnatal growth retardation, with about 15% postnatal lethality in C57BL/6, but not FVB/N crosses. This is the first example in a multicellular organism of genetic deletion of a C/D box snoRNA gene resulting in a pronounced phenotype.     

‘Complete’ trisomy 5p; de novo translocation t(2;5)(q36;p11) with isochromosome 5p

Summary A case of complete trisomy 5p due to a de novo translocation t(2;5)(q36;p11) with an isochromosome 5p is described. Complete trisomy 5p has been reported only once (Brimblecombe et al., 1977). The confusing literature relating to partial trisomy 5p is reviewed. Comparison of our case with the patients reported by Brimblecombe et al. (1977) and by Opitz and Patau (1975) is suggestive for a distinct clinical syndrome if (almost) the complete short arm of chromosome 5 is present in a trisomic state. Unfortunately the clinical findings in the case of Brimblecombe (1966, 1977) are poorly documented. The main features of this syndrome are: macrocephaly, psychomotor retardation, hypotonia, postnatal growth failure, tracheobronchial involvement, mongoloid slant of the eyes, epicanthus, low-set ears, depressed nasal bridge, short first toe, and seizures.