Fibrochondrogenesis: prenatal diagnosis and outcome

We studied 20 cases with fibrochondrogenesis (FCG) diagnosed prenatally. Four cases were diagnosed at our fetal unit, and 16 cases were identified through a review of literature (in English). The prenatal diagnosis of FCG was made in 4/20 (20%). Six (30%) patients opted for termination of pregnancy (TOP). A total of 13 cases delivered at term. Four (30.8%) had a caesarean section. Four neonates (30.7%) were stillborn and seven (53.8%) neonates died within 3 months. Two infants survived beyond 3 years of age, but both had severe global developmental delay. A molecular study of the surviving children revealed two null homozygous mutations in COL11A1 [c.4084C > T (p.R1362X) and c.3708 + c.437T > G]. We concluded that the prenatal diagnosis of fibrochondrogenesis is feasible. Fibrochondrogenesis is usually a fatal disease and survivors suffer from severe physical and neurological impairment.

Screening for neonatal hearing loss in the Eastern region of United Arab Emirates

The incidence of sensorineural hearing loss among infants in the neonatal intensive unit (NICU) is higher than in normal infants. This study determined the rate of hearing loss in healthy newborns and in NICU patients before hospital discharge at a single institution in the Eastern region of the United Arab Emirates; 96.5% of all eligible infants were screened. Hearing deficit was diagnosed in 25/13 854 healthy newborns (0.18%; 95% CI: 0.12%-0.27%) and 14/826 infants in the NICU (1.7%; 95% CI: 0.9%-2.8%). Although hearing impairment was significantly more common in those admitted to the NICU (RR = 9.4; 95% CI: 4.9-17.9), healthy newborns accounted for 25 of the 39 cases with hearing loss. The rate of congenital hearing deficit was comparable to international data. Universal screening is recommended since selective screening of high-risk infants missed two-thirds of newborns with hearing loss.

Stuve-Wiedemann syndrome: a skeletal dysplasia characterized by bowed long bones

OBJECTIVE

To describe the prenatal sonographic features of Stuve-Wiedemann syndrome (SWS).

METHODS

A retrospective review of all cases of confirmed SWS during an 8-year period was conducted. Clinical and historical data and outcome of the pregnancies were noted. Fetal biometry, skeletal survey, amniotic fluid volume and associated anomalies were recorded. A sonographic algorithm was proposed to distinguish SWS from other bent bone disorders.

RESULTS

In total, there were 10 cases, six of which were diagnosed prenatally. The main prenatal features of SWS were mild-to-moderate micromelia and bowing of the lower limb bones, affecting the tibia more than the femur. There was relative sparing of fibula and upper limb bones, with normal scapulae and clavicles. Camptodactyly was the main associated anomaly. All fetuses developed growth restriction in the late second trimester with oligohydramnios in half of the cases. These features could appear late in pregnancy. Although the thoracic dimensions were normal in the majority of fetuses, respiratory insufficiency, as a result of myotonia, was a leading cause for mortality.

CONCLUSIONS

It is possible to diagnose SWS prenatally. SWS is associated with high mortality during the first year of life, and those who survive have high morbidity.

A newly identified splice site mutation in ZMPSTE24 causes restrictive dermopathy in the Middle East

Restrictive dermopathy (RD) is a severe neonatal inherited skin syndrome of which children die shortly after birth. Clinical features include intrauterine growth retardation, taut translucent and easily eroded skin, multiple joint ankylosis and distinct facial features. RD is usually caused by homozygous or compound heterozygous mutations in ZMPSTE24, predicted to cause loss of function of the encoded zinc metalloproteinase STE24. ZMPSTE24 is essential for the processing of the nuclear intermediate filament protein prelamin A. We report two distantly related children from the United Arab Emirates with RD. Remarkably, they lived up to 2 months, suggesting some residual function of the mutant protein. We sought to confirm the diagnosis by thorough microscopic analysis of patient skin, to identify the causative mutation and to study its functional consequences. A skin biopsy was obtained and processed for light and electron microscopy. Peripheral blood leucocytes were used for DNA and RNA isolation, and detection of prelamin A by immunofluorescence. Analysis of the skin confirmed the earlier reported densely packed collagen bundles and lack of elastin fibres. In both patients a homozygous splice site mutation c.627+1G>C in ZMPSTE24 was identified. Analysis of the ZMPSTE24 mRNA revealed an in-frame exon 5 skipping. Accumulation of prelamin A could be detected at the nuclear envelope of patient blood lymphocytes. We thus report the first splice site mutation in ZMPSTE24, which is likely to be a founder mutation in the United Arab Emirates. The accumulation of prelamin A at the nuclear periphery is consistent with defective ZMPSTE24 function. Interestingly, a regular blood sample can be used to investigate prelamin A accumulation.

Flexion contractures of the lower limbs with urogenital anomalies

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Phosphorus intake in preterm babies and variation of tubular reabsorption for phosphate per liter glomerular filtrate

Inadequate low intake of phosphorus can induce a hypophosphatemic depletion syndrome resulting in hypercalcemia, hypercalciuria, hypophosphatemia, and rickets. Tubular reabsorption for phosphate per liter glomerular filtration rate (TP/GFR) has been proposed as a reliable index of renal phosphate handling for all age groups. In the present study, carried out in 12 healthy premature babies fed unmodified pooled human milk and then a preterm formula for two periods of 10 days, we demonstrated clearly that TP/GFR as well as calciuria can reflect the poor phosphorus intake and that the kidney of preterm babies is able to rapidly adapt itself to an increase in phosphorus diet content.

Aluminium absorption in infancy

The use of aluminium-containing medications and aluminium contamination of infant formulae is common. We aimed to determine whether aluminium absorption occurs after antacid ingestion. Plasma and urinary levels of aluminium were measured before and after antacid therapy in seven infants whose mean gestational age was 36 +/- 2 weeks and postnatal age 11 +/- 5 days. Antacid therapy (400-800 mumol aluminium) was given with feeds for 2 days. Plasma aluminium levels increased and reached toxic levels (0.64 +/- 0.33 mumol/L vs 3.48 +/- 2.86 mumol/L, P = 0.029). Urinary aluminium: creatinine ratio also increased. These results demonstrate that infants absorb aluminium from antacids and raise the concern of aluminium toxicity.