Table 2

 Clinical and molecular results for 22 RTT patients with large deletions of MECP2

PatientQuantitative resultQuantitative methodsIRAK1 gene also deletedX inactivation ratioAge (years)Rett typeAtypical featuresCongenital anomaliesSeverityWalkHand useSpeechScoliosisOFC
Quantitative results: exon 1, 2, 3 and 4 refer to amplicons derived from these MECP2 exons (fig 1). Del, deletion; MLPA, multiplex ligation dependent probe amplification; QF-PCR, quantitative fluorescent PCR. X inactivation: NI, not informative, NP, not performed due to insufficient DNA. Severity score – composite severity score for muscle tone, locomotor ability, scoliosis, feeding and seizures: 0  =  not present, 1  =  mild/moderately affected, 2  =  severely affected so that most severe score  = 10. OFC, current head circumference percentile. *Data unavailable, NK, not known. Patients 9, 12, 13, and 20 have been previously reported.26
1Del 1MLPAYes54:4614AtypicalAbnormal MRIHypoplastic cerebellum and cerebellar vermis9NoGrasp brieflyNoMild<3rd
2Del 1–2MLPANo65:354.2Classic3YesFinger feedsNoNo2nd–9th
3Del 1–2QF-PCRNK57:4345Classic6With supportFinger feedsNoModerate50th
4Del 1–2MLPANo80:2016.0Classic9NoNoneNoSevere<3rd
5Del 3–4.1QF-PCRNK67:334.3Classic5NoNoneNoNo2nd
6Del 3–4.1QF-PCRNK58:4212.9AtypicalEpileptic seizure onset before regression10NoGrasp brieflyNoSevere<0.4th
7Del 3–4.1QF-PCRNK75:255.2ClassicDevelopmental dysplasia of the hip (DDH)3YesNoneNoMild<0.4th
8Del 3–4Real time PCRNo90:1020.3Classic5With supportNoneNoModerate0.4th–2nd
9Del 3–4Real time PCRNo90:1014.6Classic3YesNoneNoMild9th
10Del 3–4Real time PCRNo60:4021.4Classic4NoNoneNoMild0.4th–2nd
11Del 3–4.3QF-PCR MLPAYes57:4310Classic6NoNoneNoMild0.4th–2nd
12Del 3–4.3QF-PCR MLPAYes61:397Classic6NoGrasp brieflyNoModerate<0.4th
13Del 3–4.3MLPANoNP19.2Classic5With supportNoneNoMild<3rd
14Del 3–4.3MLPANo56:4415.0Classic7NoNoneNoMild0.4th–2nd
15Del 3–4.3MLPAYesNP6.5Classic3YesNonePossiblyMild2nd–9th
16Del 4.1–4.3MLPANo67:3312.3AtypicalPreserved head growth6NoNoneNoModerate50th
17Del 4Real time PCRYes70:304.6Classic3YesGrasp brieflyNoModerate50th
18Del 4.2MLPANo58:424.6ClassicCleft palate9NoGrasp brieflyNoMild<0.4th
19Del 4.2–4.3QF-PCR MLPANoNI38.0ClassicAtretic right ear and absent auditory meatus4YesFinger feedsNoModerate<0.4th
20Del 4.2–4.4QF-PCR MLPANo85:154.4AtypicalMultiple congenital anomalies, very abnormal early developmentTransposition great arteries, right choanal stenosis, laryngeal web, cleft palate8NoNoneNoModerate<0.4th
21Del 4.3MLPANo58:4214.3Classic*YesNKNoNK<3rd
22Del 4.3QF-PCR MLPANoNP12.4Classic8NoGrasp brieflyNoSevere<0.4th