Case:Patient 1, Male, 4 y/o, German and Thai

DiseaseAssertion:FOXG1 syndrome

FamilyInfo: Non-consanguineous parents. De novo. Patient 1 has maternally inherited duplications at 15q21.12(47292250-47309868)x3 and Xp22.31(6451676-8115124)x3 of unknown clinical significance.

ParentalGenotype:Not provided

CasePresentingHPOs:HP:0002197, HP:0005484, HP:0011344, HP:0001252, HP:0020045,HP:0000540, HP:0010808, HP:0002019, HP:0003781, HP:0012741, HP:0002421, HP:0000748, HP:0003763, HP:5200017, HP:0025112, HP:0000957

CaseHPOFreeText: At 19 months, could not sit independently and no speech development. Stereotypic hand and head movements. High pain tolerance. X-ray at age 2 showed broad ribs. Improved head control by age 4.

CaseNotHPO:HP:0410263, HP:0002376

CaseNotHPOFreeText:Dysmorphic features. breathing abnormalities

CasePreviousTesting:No previous testing

PreviouslyPublished:Not previously published

GenotypingMethod:Mate-pair sequencing, Sanger sequencing

Gene:FOXG1

Variant:46,XY,t(9;14)(q22.3;q11.2)dn

HGVS:Not provided

ClinVarID:426096

gnomAD:Not provided

Case:Patient 3, Male, 1 y/o, Brazilian

DiseaseAssertion: FOXG1 syndrome

FamilyInfo: Non-consanguineous parents

ParentalGenotype: No family testing mentioned.

CasePresentingHPOs: HP:0000252, HP:0001252, HP:0000486

CaseHPOFreeText: Developed microcephaly within 1 year. Developmental delay, unable to sit without assistance at 1 year old. Central Nervous System (CNS) MRI showed a volumetric reduction of the cerebral parenchyma, hypomyelination, and hypoplasia of corpus callosum mainly involving the anterior part and prominent lateral ventricles

CaseNotHPO: HP:0030917

CaseNotHPOFreeText: Normal length, weight, HC at birth. No retinal abnormalities.

CasePreviousTesting: Not asserted.

PreviouslyPublished: Not previously published.

GenotypingMethod: Sanger sequencing, mate-pair sequencing

Gene: FOXG1

Variant: 46,XY,t(2;14)(q37;q11.2)dn

HGVS: Not provided.

ClinVarID:426094

gnomAD:Not provided

Case:Patient 2, Female, 5 y/o, Brazilian

DiseaseAssertion:quadriplegic cerebral palsy with axial hypotonia and distal spasticity

FamilyInfo: Non-consanguineous parents. Parents had normal karyotypes. Older sister was clinically normal.

ParentalGenotype: Normal karyotypes for both parents.

CasePresentingHPOs: HP:0002098, HP:0010959, HP:0008755, HP:0002090, HP:0032661, HP:0001274, HP:0011344, HP:0001249, HP:0001344, HP:0000748, HP:0034435, HP:0000486, HP:0000483, HP:0200136

CaseHPOFreeText: Dilated superficial blood vessels seen on brain MRI.

CaseNotHPO:N/A

CaseNotHPOFreeText: N/A

CasePreviousTesting: Not asserted

PreviouslyPublished: Not previously published

GenotypingMethod:Mate-pair sequencing, Sanger sequencing, chromosome analysis

Gene: FOXG1

Variant: 46,XX,t(4;14)(q27;q13)dn

HGVS: Not provided

ClinVarID: 426095

gnomAD: Not provided

Case: Patient 1, female, 2 years old

DiseaseAssertion: Rett Syndrome

FamilyInfo: DeNovo. Patient 1 was the second child of a nonconsanguineous Chinese couple. Patient 1 was born at full term with a birth weight of 3.83 kg.

ParentalGenotype(s):Not provided

CasePresentingHPOs:HP:0011344, HP:0001250, HP:0001252, HP:0000252, HP:0000748, HP:0003763, HP:0005469, HP:0000486, HP:0012171.

CaseHPOFreeRext:Patient 1 presents with severe global developmental delay, epilepsy, and hypotonia. The Patient History contains all of Patient 1's phenotypes along with the progression of her condition.

Patient History

@ 3 months - Patient 1 had microcephaly (head circumference was less than 3rd percentile with a body weight and body height at 75th percentile). Patient 1 had hypotonia.

Patient 1 was given a metabolic screening, a muscle enzyme, and a brain tomography with normal results.

@ 6 months - Patient 1 had microcephaly, flat occiput, right divergent squint, and hypotonia. No syndromal diagnosis could be ascertained at that time.

@ 2 years - Patient 1 had epilepsy.

Patient 1 had severe global development delay.

Patient 1 was given an EEG which showed nonspecific background slowing, but no epileptiform abnormalities. Patient 1 was also given a brain MRI which showed mild thinning of corpus callosum without major structural defect. Patient 1 had no developmental regression but she developed stereotypical hand movements, bruxism, and occasional outburst of laughter.

Based on these phenotypes, Angelman/Rett Syndrome was suspected.

CaseNOTHPOs: HP:0002353.

CaseNOTHPOFreeText: Patient 1 was given an EEG which detected no epileptic abnormalites.

CasePreviousTesting: Genetic investigations (including methylation-specific multiplex ligation-dependent probe amplification (MS-MLLPA)) was conducted for Angelman Syndrome, UBE3A gene, MECP gene, and array CGH. These studies were negative. A FOXG1 related disease was suspected

PreviouslyPublished:Not previously published

GenotypingMethod: A FOXG1 gene test showed a de novo frameshift pathogenic mutation FOXG1 {NM_005249.3} c. 396_397ins26; FOXG1{NP_005240.3} :(p. Gly133TRPfs*68) which confirmed the diagnosis of a FOXG1 related congenital variant of Rett Syndrome.

Gene:FOXG1

Variant: (NM_005249.3) c. 396_397ins26 (p. Gly133Trpfs*68)

HGVS:Not provided

ClinVarID:Not found

CAID:Not found

gnomAD:Not found