The mitochondrial aspartate-glutamate carrier isoform 1 (AGC1), specific to neurons and muscle, supplies aspartate to the cytosol and, as a component of the malate-aspartate shuttle, enables mitochondrial oxidation of cytosolic NADH, thought to be important in providing energy for neurons in the central nervous system. We describe AGC1 deficiency, a novel syndrome characterized by arrested psyc...

X-linked myotubular myopathy (McKusick no. 31040) is a congenital myopathy in which affected male subjects typically present with severe hypotonia and respiratory distress at birth. Surviving patients have prolonged ventilator dependence and grossly delayed motor milestones but usually have intact intelligence.1-3 However, the long-term prognosis as reported in the literature is generally poor,...

Three unrelated Puerto Rican boys, ranging in age from 3 to 4 years, had marked, central, non-progressive hypotonia, chronic constipation, severe psychomotor retardation, seizures or abnormal electroencephalograph or both, abnormal dermatoglyphics, delayed bone age, dysharmonic skeletal maturation, and preponderance and larger size of type 2 muscle fibres. Additional findings included narrow, h...

The presentation of the typical characteristics of the acrocallosal syndrome (ACLS) are hypoplasia/agenesis of corpus callosum, moderate to severe mental retardation, characteristic craniofacial abnormalities, distinctive digital malformation, and growth retardation in a neonate. An Indian neonate presented on day 1 of life (youngest in the literature to be reported) with combination of abnorma...

X-linked myotubular myopathy (McKusick no. 31040) is a congenital myopathy in which affected male subjects typically present with severe hypotonia and respiratory distress at birth. Surviving patients have prolonged ventilator dependence and grossly delayed motor milestones but usually have intact intelligence.1-3 However, the long-term prognosis as reported in the literature is generally poor,...

The GRIN2B (glutamate receptor, ionotropic, N-methyl-d-aspartate 2B) gene, located in the short arm of chromosome 12, encoding the NR2B subunit of the N-methyl-D-aspartate receptor, has recently been recognized to play an important role in corticogenesis and brain plasticity. Deletions in the short arm of chromosome 12 are rare. Hemizygous loss of function of the GRIN2B gene results in developm...

In 1911, Oppenheim coined the term ‘dystonia’ to describe disordered motor control, characterised by an association of hypotonia and tonic muscle spasm. Focal hand dystonia is one form of this disorder, in which symptoms are often task-specific and occur during skilled movements such as writing (writer’s cramp) or playing a musical instrument (musician’s cramp). Much research has been conducted...

Interstitial deletions of the long arm of chromosome 14 are infrequent. Molecular and clinical studies on patients with deletions involving 14q11.2-q21 have recently been reported. Most of these deletion patients share common clinical signs, such as midline defects of the central nervous system, feeding problems, growth abnormalities, hypotonia, developmental delay, mental retardation, and cran...

We report a female patient with a de novo balanced translocation, 46,X,t(X;2)(p11.2;q37)dn, who exhibits seizures, capillary abnormality, developmental delay, infantile hypotonia, and obesity. The 2q37 breakpoint observed in association with the seizure phenotype is of particular interest, because it lies near loci implicated in epilepsy in humans and mice. Fluorescence in situ hybridization ma...

ehlers-danlos syndrome (eds vi)(omim 225400) is an autosomal recessive disease of the connective tissue. it is characterized by severe hypotonia at birth, progressive kyphoscoliosis, skin hyperelasticity, joint hypermobility, microcornea, rupture of arteries and eye globe, and osteopenia. collagen lysyl hydroxylase is deficient in these patients. deficiency of the activity of lysyl hydroxylase,...