Abnormal myelin formation in rhizomelic chondrodysplasia punctata type 2 (DHAPAT-deficiency)

The case of a Yemeni girl with isolated peroxisomal acyl-CoA:dihydroxyacetonephosphate acyltransferase (DHAPAT) deficiency is reported. She had rhizomelic chondrodysplasia punctata, microcephaly, failure to thrive, delayed motor and mental development, and spastic quadriplegia. Deficient de novo plasmalogen synthesis in her fibroblasts as a result of low DHAPAT activity was found, while her very-long-chain fatty acid profile, phytanic acid concentration, alkyl-dihydroxyacetonephosphate synthase (alkyl-DHAP synthase) activity, and peroxisomal 3-ketoacyl-CoA thiolase protein were normal. A mutation in her DHAPAT complementary DNA resulted in the substitution of an arginine residue in the protein at position 211 by a histidine (R211H). Magnetic resonance imaging showed abnormal white matter signal in the centrum semiovale involving the arcuate fibers, while the corpus callosum was normal. DHAPAT and alkyl-DHAP synthase initiate the synthesis of plasmalogens, which are major constituents of myelin phospholipids. The reported girl's abnormal formation of myelin is probably related to the inadequacy of plasmalogen biosynthesis, which is likely to be due to deficient DHAPAT activity.     

An autosomal recessive syndrome of nasal anomalies associated with renal and anorectal malformations

We report a consanguineous Arab family with four children affected with bifid nose associated with renal agenesis and variable degree of anorectal malformations. We suggest that the combination of abnormalities in these children represent a previously undescribed autosomal recessive syndrome.     

An autosomal recessive syndrome of choanal atresia,hypothelia/athelia and thyroid gland anomalies overlapping bamforth syndrome,ANOTHER syndrome and methimazole embryopathy

Two sibs from an inbred Arab family are described with an autosomal syndrome of choanal atresia, hypothelia/athelia and thyroid gland anomalies overlapping Bamforth syndrome, ANOTHER syndrome and methimazole embryopathy. In one case the syndrome described was lethal. Cases with similar features are reviewed and genetic mutations discussed.     

Pattern of central nervous system anomalies in a population with a high rate of consanguineous marriages

Nine thousand six hundred and ten births were prospectively studied in the three major hospitals in Al-Ain, United Arab Emirates (UAE) between October 1995 and January 1997. Babies suspected of, or diagnosed, as having central nervous system (CNS) abnormalities were evaluated by a neonatologist, a clinical geneticist and a pediatric neurologist. Brain computerized tomography/magnetic resonance imaging (CT/MRI) was performed on all babies suspected of having CNS abnormalities. In addition, metabolic screening and chromosome analysis were also performed when indicated. Of the 225 babies with congenital anomalies identified, 31 had CNS abnormalities (3.2/1000). Syndromic abnormalities of the CNS were present in 13 cases (42%), chromosomal abnormalities in one case (3.2%) and the rest included: neural tube defect (NTD) in 11 cases (36%), holoprosencephaly in two cases (6.4%) and hydrocephalus in four cases (12.9%). Detailed analysis of the syndromic types revealed that out of the 13 cases, 12 were inherited as autosomal recessive (AR) and in one case the inheritance was undetermined. Consanguinity with high level of inbreeding was present in 12 cases and the majority of the syndromes identified were extremely rare. The study indicates that CNS anomalies are fairly common in the UAE, particularly, the recessive syndromic types. Careful and detailed analysis of such anomalies is required so that accurate genetic advice can be given.     

Congenital bowing of the long bones associated with camptodactyly, talipes equinovarus and agenesis of the corpus callosum

We report a baby with congenital bowing of the long bones, camptodactyly, talipes equinovarus and radiological features resembling both Stüve-Wiedemann syndrome and Schwartz-Jampel syndrome type 2. The baby had, in addition, agenesis of the corpus callosum. This feature has not been reported in either of these syndromes. It is possible that this baby has a previously undescribed syndrome.     

A new autosomal recessive syndrome of ocular colobomas, ichthyosis, brain malformations and endocrine abnormalities in an inbred Emirati family

We report on an inbred Emirati family of Baluchi origin with ocular colobomas, ichthyosis, and endocrine abnormalities associated with midline brain malformations and mental retardation. All affected children had ocular colobomas, developmental delay and midline brain malformations. Hypoplastic pituitary gland was present in all three investigated children. Ichthyosiform dermatitis appeared in infancy in all surviving children. Other variable features include congenital heart defects, hypertrichosis and dark skin involving the dorsum of hands and feet associated with mild degree of palmo-plantar keratoderma. Some of the features in this family overlap the CHIME (Coloboma of the eye, Heart defect, Ichthyosiform dermatosis, Mental retardation, and Ear defect) syndrome. However, several features described in CHIME syndrome were not present in these children. These include deafness, seizures, oligodontia, and hair abnormalities. Some of the features in these children also overlap with septo-optic dysplasia (SOD) but optic nerve hypoplasia, mandatory for the diagnosis of SOD, was present in one child only. We suggest that these children have a new autosomal recessive syndrome of ocular colobomas and ichthyosis.