Table 1

Clinical features of eight affected individuals from families A and B

PatientFamily AFamily B
1 (male)2 (male)3 (male)4 (male)5 (female)6 (female)7 (male)8 (male)
Gestation at birth (weeks)3840404041394040
Birth weight (kg)2.26 (2nd centile)3.3 (25th centile)3.85 (50th–75th centile)3.74 (50th–75th centile)4.05 (91st centile)3.37 (mean)3.4 (−0.9 SD)3.2 (−1.5 SD)
Birth OFC (cm)36.0 (91st–98th centile)36.4 (75th–91st centile)38.2 (98th–99th centile)38.4 (98th–99th centile)35.4 (75th–91st centile)33 (−1.2 SD)34 (−1.8 SD)34.5 (−1.1 SD)
Lower limbsBilateral spasticityBilateral spasticityBilateral spasticityBilateral spasticityBilateral spasticityBilateral spasticity
Upper limbsNormal examinationDystonic posturingNormal examinationNormal examinationIncreased tone and hyperreflexiaNormalDystonic posturingNormal
EpilepsyMyoclonic and tonic–clonic epilepsy from 7 monthsMyoclonic and tonic–clonic seizures from 5 yearsNoneTonic–clonic epilepsy from 10 yearsMyoclonic epilepsy from infancyNoneMyoclonic seizures, focal epilepsyNone
Recent growth parameters
Age18 years15 years22 years19 years3 years10 years 11 months7 years 8 months7 years 8 months
BMI (kg/m2)33.33755.7 50.4 20.624.821.1719.32
OFC (cm)59 (75th–91st centile)59 (91st–98th centile)64 (>99th centile)63 (>99th centile)47.2 (<0.4th centile) 54 (+0.5 SD)53 (+0.2 SD) 53 (+0.2 SD)
MobilityNever walkedNever walkedAge 16: mobile for short distances with callipersAge 15: 10–15 steps with a rollatorNever walkedUnstable, waddling gaitUnstable, waddling gaitUnstable, waddling gait
Ophthalmic findingsDivergent strabismusDivergent strabismusRight divergent strabismus, bilateral myopia, right macular hypoplasia, retinal dystrophyDivergent strabismus, myopia, bilateral retinal dystrophySevere myopia, left divergent squint, sluggish pupil responses, retinal dystrophyConvergent strabismus, bilateral myopia, retinal dystrophy
HearingBilateral sensorineural loss (40 dB)No abnormalityBilateral sensorineural loss (30 dB)No abnormalityBilateral sensorineural loss (40 dB)No abnormalityNo abnormalityNo abnormality
Neurological investigationsCT scan: cerebral underdevelopment and marked atrophy of frontal and temporal lobes.
EEG: consistent with myoclonic epilepsy
No cranial imaging performedCT scan: generalised cerebral atrophyEEG: normal
CT scan: ventricular dilatation
EEG: focal and generalised spike-like discharges. Nerve conduction studies normal.
MRI brain: prominent generalised cerebral and brain stem atrophy, disproportion between grey and white matters.
ERG: Consistent with cone-rod dystrophy
MRI: hypoplastic corpus callosum
EEG: normal
MRI: hypoplastic corpus callosum
EEG: consistent with myoclonic epilepsy
MRI: enlarged ventricles
EEG: normal
SkeletalLeft talipes equinovarus
Erb's palsy
Right subtalar fusion age 9 years
Calcaneovalgus deformity of feetKyphoscoliosis
Bilateral hip dislocation
Pes planusMild talipes equinovarus
  • BMI, body mass index; ERG, electroretinography; OFC, occipitofrontal head circumference.